diff --git a/src/pretix/api/serializers/order.py b/src/pretix/api/serializers/order.py
index 7738d99ac9..e1bd8fd0b1 100644
--- a/src/pretix/api/serializers/order.py
+++ b/src/pretix/api/serializers/order.py
@@ -14,8 +14,8 @@ from pretix.api.serializers.i18n import I18nAwareModelSerializer
 from pretix.base.channels import get_all_sales_channels
 from pretix.base.i18n import language
 from pretix.base.models import (
-    Checkin, Invoice, InvoiceAddress, InvoiceLine, Order, OrderPosition,
-    Question, QuestionAnswer,
+    Checkin, Invoice, InvoiceAddress, InvoiceLine, Item, ItemVariation, Order,
+    OrderPosition, Question, QuestionAnswer, SubEvent,
 )
 from pretix.base.models.orders import (
     CartPosition, OrderFee, OrderPayment, OrderRefund,
@@ -337,6 +337,23 @@ class OrderSerializer(I18nAwareModelSerializer):
         return instance
 
 
+class PriceCalcSerializer(serializers.Serializer):
+    item = serializers.PrimaryKeyRelatedField(queryset=Item.objects.none(), required=False, allow_null=True)
+    variation = serializers.PrimaryKeyRelatedField(queryset=ItemVariation.objects.none(), required=False, allow_null=True)
+    subevent = serializers.PrimaryKeyRelatedField(queryset=SubEvent.objects.none(), required=False, allow_null=True)
+    locale = serializers.CharField(allow_null=True, required=False)
+
+    def __init__(self, *args, **kwargs):
+        event = kwargs.pop('event')
+        super().__init__(*args, **kwargs)
+        self.fields['item'].queryset = event.items.all()
+        self.fields['variation'].queryset = ItemVariation.objects.filter(item__event=event)
+        if event.has_subevents:
+            self.fields['subevent'].queryset = event.subevents.all()
+        else:
+            del self.fields['subevent']
+
+
 class AnswerCreateSerializer(I18nAwareModelSerializer):
 
     class Meta:
diff --git a/src/pretix/api/views/order.py b/src/pretix/api/views/order.py
index aa2bd94258..04e2b24935 100644
--- a/src/pretix/api/views/order.py
+++ b/src/pretix/api/views/order.py
@@ -24,11 +24,12 @@ from pretix.api.models import OAuthAccessToken
 from pretix.api.serializers.order import (
     InvoiceSerializer, OrderCreateSerializer, OrderPaymentSerializer,
     OrderPositionSerializer, OrderRefundCreateSerializer,
-    OrderRefundSerializer, OrderSerializer,
+    OrderRefundSerializer, OrderSerializer, PriceCalcSerializer,
 )
+from pretix.base.i18n import language
 from pretix.base.models import (
-    CachedCombinedTicket, CachedTicket, Device, Event, Invoice, Order,
-    OrderPayment, OrderPosition, OrderRefund, Quota, TeamAPIToken,
+    CachedCombinedTicket, CachedTicket, Device, Event, Invoice, InvoiceAddress,
+    Order, OrderPayment, OrderPosition, OrderRefund, Quota, TeamAPIToken,
     generate_position_secret, generate_secret,
 )
 from pretix.base.payment import PaymentException
@@ -42,10 +43,12 @@ from pretix.base.services.orders import (
     OrderChangeManager, OrderError, approve_order, cancel_order, deny_order,
     extend_order, mark_order_expired, mark_order_refunded,
 )
+from pretix.base.services.pricing import get_price
 from pretix.base.services.tickets import generate
 from pretix.base.signals import (
     order_modified, order_placed, register_ticket_outputs,
 )
+from pretix.base.templatetags.money import money_filter
 
 
 class OrderFilter(FilterSet):
@@ -622,6 +625,83 @@ class OrderPositionViewSet(mixins.DestroyModelMixin, viewsets.ReadOnlyModelViewS
                 return prov
         raise NotFound('Unknown output provider.')
 
+    @action(detail=True, methods=['POST'], url_name='price_calc')
+    def price_calc(self, request, *args, **kwargs):
+        """
+        This calculates the price assuming a change of product or subevent. This endpoint
+        is deliberately not documented and considered a private API, only to be used by
+        pretix' web interface.
+
+        Sample input:
+
+        {
+            "item": 2,
+            "variation": null,
+            "subevent": 3
+        }
+
+        Sample output:
+
+        {
+            "gross": "2.34",
+            "gross_formatted": "2,34",
+            "net": "2.34",
+            "tax": "0.00",
+            "rate": "0.00",
+            "name": "VAT"
+        }
+        """
+        serializer = PriceCalcSerializer(data=request.data, event=request.event)
+        serializer.is_valid(raise_exception=True)
+        data = serializer.validated_data
+        pos = self.get_object()
+
+        try:
+            ia = pos.order.invoice_address
+        except InvoiceAddress.DoesNotExist:
+            ia = InvoiceAddress()
+
+        kwargs = {
+            'item': pos.item,
+            'variation': pos.variation,
+            'voucher': pos.voucher,
+            'subevent': pos.subevent,
+            'addon_to': pos.addon_to,
+            'invoice_address': ia,
+        }
+
+        if data.get('item'):
+            item = data.get('item')
+            kwargs['item'] = item
+
+            if item.has_variations:
+                variation = data.get('variation') or pos.variation
+                if not variation:
+                    raise ValidationError('No variation given')
+                if variation.item != item:
+                    raise ValidationError('Variation does not belong to item')
+                kwargs['variation'] = variation
+            else:
+                variation = None
+                kwargs['variation'] = None
+
+            if pos.voucher and not pos.voucher.applies_to(item, variation):
+                kwargs['voucher'] = None
+
+        if data.get('subevent'):
+            kwargs['subevent'] = data.get('subevent')
+
+        price = get_price(**kwargs)
+        with language(data.get('locale') or self.request.event.settings.locale):
+            return Response({
+                'gross': price.gross,
+                'gross_formatted': money_filter(price.gross, self.request.event.currency, hide_currency=True),
+                'net': price.net,
+                'rate': price.rate,
+                'name': str(price.name),
+                'tax': price.tax,
+            })
+
     @action(detail=True, url_name='download', url_path='download/(?P<output>[^/]+)')
     def download(self, request, output, **kwargs):
         provider = self._get_output_provider(output)
diff --git a/src/pretix/base/services/orders.py b/src/pretix/base/services/orders.py
index 731d14ed4d..9966a202db 100644
--- a/src/pretix/base/services/orders.py
+++ b/src/pretix/base/services/orders.py
@@ -872,8 +872,8 @@ class OrderChangeManager:
         'addon_invalid': _('The selected base position does not allow you to add this product as an add-on.'),
         'subevent_required': _('You need to choose a subevent for the new position.'),
     }
-    ItemOperation = namedtuple('ItemOperation', ('position', 'item', 'variation', 'price'))
-    SubeventOperation = namedtuple('SubeventOperation', ('position', 'subevent', 'price'))
+    ItemOperation = namedtuple('ItemOperation', ('position', 'item', 'variation'))
+    SubeventOperation = namedtuple('SubeventOperation', ('position', 'subevent'))
     PriceOperation = namedtuple('PriceOperation', ('position', 'price'))
     CancelOperation = namedtuple('CancelOperation', ('position',))
     AddOperation = namedtuple('AddOperation', ('item', 'variation', 'price', 'addon_to', 'subevent'))
@@ -893,33 +893,18 @@ class OrderChangeManager:
         self.notify = notify
         self._invoice_dirty = False
 
-    def change_item(self, position: OrderPosition, item: Item, variation: Optional[ItemVariation], keep_price=False):
+    def change_item(self, position: OrderPosition, item: Item, variation: Optional[ItemVariation]):
         if (not variation and item.has_variations) or (variation and variation.item_id != item.pk):
             raise OrderError(self.error_messages['product_without_variation'])
 
-        if keep_price:
-            price = TaxedPrice(gross=position.price, net=position.price - position.tax_value,
-                               tax=position.tax_value, rate=position.tax_rate,
-                               name=position.tax_rule.name if position.tax_rule else None)
-        else:
-            price = get_price(item, variation, voucher=position.voucher, subevent=position.subevent,
-                              invoice_address=self._invoice_address)
-
-        if price is None:  # NOQA
-            raise OrderError(self.error_messages['product_invalid'])
-
         new_quotas = (variation.quotas.filter(subevent=position.subevent)
                       if variation else item.quotas.filter(subevent=position.subevent))
         if not new_quotas:
             raise OrderError(self.error_messages['quota_missing'])
 
-        if self.order.event.settings.invoice_include_free or price.gross != Decimal('0.00') or position.price != Decimal('0.00'):
-            self._invoice_dirty = True
-
-        self._totaldiff += price.gross - position.price
         self._quotadiff.update(new_quotas)
         self._quotadiff.subtract(position.quotas)
-        self._operations.append(self.ItemOperation(position, item, variation, price))
+        self._operations.append(self.ItemOperation(position, item, variation))
 
     def change_subevent(self, position: OrderPosition, subevent: SubEvent):
         price = get_price(position.item, position.variation, voucher=position.voucher, subevent=subevent,
@@ -933,19 +918,15 @@ class OrderChangeManager:
         if not new_quotas:
             raise OrderError(self.error_messages['quota_missing'])
 
-        if self.order.event.settings.invoice_include_free or price.gross != Decimal('0.00') or position.price != Decimal('0.00'):
-            self._invoice_dirty = True
-
-        self._totaldiff += price.gross - position.price
         self._quotadiff.update(new_quotas)
         self._quotadiff.subtract(position.quotas)
-        self._operations.append(self.SubeventOperation(position, subevent, price))
+        self._operations.append(self.SubeventOperation(position, subevent))
 
     def regenerate_secret(self, position: OrderPosition):
         self._operations.append(self.RegenerateSecretOperation(position))
 
     def change_price(self, position: OrderPosition, price: Decimal):
-        price = position.item.tax(price)
+        price = position.item.tax(price, base_price_is='gross')
 
         self._totaldiff += price.gross - position.price
 
@@ -1102,14 +1083,11 @@ class OrderChangeManager:
                     'new_variation': op.variation.pk if op.variation else None,
                     'old_price': op.position.price,
                     'addon_to': op.position.addon_to_id,
-                    'new_price': op.price.gross
+                    'new_price': op.position.price
                 })
                 op.position.item = op.item
                 op.position.variation = op.variation
-                op.position.price = op.price.gross
-                op.position.tax_rate = op.price.rate
-                op.position.tax_value = op.price.tax
-                op.position.tax_rule = op.item.tax_rule
+                op.position._calculate_tax()
                 op.position.save()
             elif isinstance(op, self.SubeventOperation):
                 self.order.log_action('pretix.event.order.changed.subevent', user=self.user, auth=self.auth, data={
@@ -1118,13 +1096,9 @@ class OrderChangeManager:
                     'old_subevent': op.position.subevent.pk,
                     'new_subevent': op.subevent.pk,
                     'old_price': op.position.price,
-                    'new_price': op.price.gross
+                    'new_price': op.position.price
                 })
                 op.position.subevent = op.subevent
-                op.position.price = op.price.gross
-                op.position.tax_rate = op.price.rate
-                op.position.tax_value = op.price.tax
-                op.position.tax_rule = op.position.item.tax_rule
                 op.position.save()
             elif isinstance(op, self.PriceOperation):
                 self.order.log_action('pretix.event.order.changed.price', user=self.user, auth=self.auth, data={
@@ -1135,9 +1109,7 @@ class OrderChangeManager:
                     'new_price': op.price.gross
                 })
                 op.position.price = op.price.gross
-                op.position.tax_rate = op.price.rate
-                op.position.tax_value = op.price.tax
-                op.position.tax_rule = op.position.item.tax_rule
+                op.position._calculate_tax()
                 op.position.save()
             elif isinstance(op, self.CancelOperation):
                 for opa in op.position.addons.all():
diff --git a/src/pretix/control/forms/orders.py b/src/pretix/control/forms/orders.py
index 37eee6d3d7..4d11a05eeb 100644
--- a/src/pretix/control/forms/orders.py
+++ b/src/pretix/control/forms/orders.py
@@ -9,9 +9,7 @@ from django.utils.timezone import now
 from django.utils.translation import pgettext_lazy, ugettext_lazy as _
 
 from pretix.base.forms import I18nModelForm, PlaceholderValidator
-from pretix.base.models import (
-    InvoiceAddress, Item, ItemAddOn, Order, OrderPosition,
-)
+from pretix.base.models import InvoiceAddress, ItemAddOn, Order, OrderPosition
 from pretix.base.models.event import SubEvent
 from pretix.base.services.pricing import get_price
 from pretix.control.forms.widgets import Select2
@@ -150,15 +148,6 @@ class CommentForm(I18nModelForm):
         }
 
 
-class SubEventChoiceField(forms.ModelChoiceField):
-    def label_from_instance(self, obj):
-        p = get_price(self.instance.item, self.instance.variation,
-                      voucher=self.instance.voucher,
-                      subevent=obj)
-        return '{} – {} ({})'.format(obj.name, obj.get_date_range_display(),
-                                     p.print(self.instance.order.event.currency))
-
-
 class OtherOperationsForm(forms.Form):
     recalculate_taxes = forms.BooleanField(
         label=_('Re-calculate taxes'),
@@ -265,12 +254,13 @@ class OrderPositionAddForm(forms.Form):
 
 
 class OrderPositionChangeForm(forms.Form):
-    itemvar = forms.ChoiceField()
-    subevent = SubEventChoiceField(
+    itemvar = forms.ChoiceField(
+        required=False,
+    )
+    subevent = forms.ModelChoiceField(
         SubEvent.objects.none(),
-        label=pgettext_lazy('subevent', 'New date'),
-        required=True,
-        empty_label=None
+        required=False,
+        empty_label=_('(Unchanged)')
     )
     price = forms.DecimalField(
         required=False,
@@ -278,53 +268,49 @@ class OrderPositionChangeForm(forms.Form):
         localize=True,
         label=_('New price (gross)')
     )
-    operation = forms.ChoiceField(
+    operation_secret = forms.BooleanField(
         required=False,
-        widget=forms.RadioSelect,
-        choices=(
-            ('product', 'Change product'),
-            ('price', 'Change price'),
-            ('subevent', 'Change event date'),
-            ('cancel', 'Remove product'),
-            ('split', 'Split into new order'),
-            ('secret', 'Regenerate secret'),
-        )
+        label=_('Generate a new secret')
+    )
+    operation_cancel = forms.BooleanField(
+        required=False,
+        label=_('Cancel this position')
+    )
+    operation_split = forms.BooleanField(
+        required=False,
+        label=_('Split into new order')
     )
-    change_product_keep_price = forms.BooleanField(required=False)
 
     def __init__(self, *args, **kwargs):
         instance = kwargs.pop('instance')
         initial = kwargs.get('initial', {})
 
-        try:
-            ia = instance.order.invoice_address
-        except InvoiceAddress.DoesNotExist:
-            ia = None
-
-        if instance:
-            try:
-                if instance.variation:
-                    initial['itemvar'] = '%d-%d' % (instance.item.pk, instance.variation.pk)
-                elif instance.item:
-                    initial['itemvar'] = str(instance.item.pk)
-            except Item.DoesNotExist:
-                pass
-
-            if instance.item.tax_rule and not instance.item.tax_rule.price_includes_tax:
-                initial['price'] = instance.price - instance.tax_value
-            else:
-                initial['price'] = instance.price
-        initial['subevent'] = instance.subevent
+        if instance.item.tax_rule and not instance.item.tax_rule.price_includes_tax:
+            initial['price'] = instance.price - instance.tax_value
+        else:
+            initial['price'] = instance.price
 
         kwargs['initial'] = initial
         super().__init__(*args, **kwargs)
         if instance.order.event.has_subevents:
-            self.fields['subevent'].instance = instance
             self.fields['subevent'].queryset = instance.order.event.subevents.all()
+            self.fields['subevent'].widget = Select2(
+                attrs={
+                    'data-model-select2': 'event',
+                    'data-select2-url': reverse('control:event.subevents.select2', kwargs={
+                        'event': instance.order.event.slug,
+                        'organizer': instance.order.event.organizer.slug,
+                    }),
+                    'data-placeholder': _('(Unchanged)')
+                }
+            )
+            self.fields['subevent'].widget.choices = self.fields['subevent'].choices
         else:
             del self.fields['subevent']
 
-        choices = []
+        choices = [
+            ('', _('(Unchanged)'))
+        ]
         for i in instance.order.event.items.prefetch_related('variations').all():
             pname = str(i)
             if not i.is_available():
@@ -333,14 +319,10 @@ class OrderPositionChangeForm(forms.Form):
 
             if variations:
                 for v in variations:
-                    p = get_price(i, v, voucher=instance.voucher, subevent=instance.subevent,
-                                  invoice_address=ia)
                     choices.append(('%d-%d' % (i.pk, v.pk),
-                                    '%s – %s (%s)' % (pname, v.value, p.print(instance.order.event.currency))))
+                                    '%s – %s' % (pname, v.value)))
             else:
-                p = get_price(i, None, voucher=instance.voucher, subevent=instance.subevent,
-                              invoice_address=ia)
-                choices.append((str(i.pk), '%s (%s)' % (pname, p.print(instance.order.event.currency))))
+                choices.append((str(i.pk), pname))
         self.fields['itemvar'].choices = choices
         change_decimal_field(self.fields['price'], instance.order.event.currency)
 
diff --git a/src/pretix/control/templates/pretixcontrol/base.html b/src/pretix/control/templates/pretixcontrol/base.html
index 49b1484947..7475dcc07a 100644
--- a/src/pretix/control/templates/pretixcontrol/base.html
+++ b/src/pretix/control/templates/pretixcontrol/base.html
@@ -43,6 +43,7 @@
             <script type="text/javascript" src="{% static "pretixcontrol/js/ui/subevent.js" %}"></script>
             <script type="text/javascript" src="{% static "pretixcontrol/js/ui/question.js" %}"></script>
             <script type="text/javascript" src="{% static "pretixcontrol/js/ui/mail.js" %}"></script>
+            <script type="text/javascript" src="{% static "pretixcontrol/js/ui/orderchange.js" %}"></script>
             <script type="text/javascript" src="{% static "pretixcontrol/js/ui/typeahead.js" %}"></script>
             <script type="text/javascript" src="{% static "pretixcontrol/js/ui/quicksetup.js" %}"></script>
             <script type="text/javascript" src="{% static "pretixbase/js/details.js" %}"></script>
diff --git a/src/pretix/control/templates/pretixcontrol/order/change.html b/src/pretix/control/templates/pretixcontrol/order/change.html
index 48f51fe7e6..7b84d542c0 100644
--- a/src/pretix/control/templates/pretixcontrol/order/change.html
+++ b/src/pretix/control/templates/pretixcontrol/order/change.html
@@ -1,6 +1,7 @@
 {% extends "pretixcontrol/event/base.html" %}
 {% load i18n %}
 {% load bootstrap3 %}
+{% load money %}
 {% block title %}
     {% blocktrans trimmed with code=order.code %}
         Change order: {{ code }}
@@ -71,92 +72,87 @@
                     </h3>
                 </div>
                 <div class="panel-body">
-                    <div class="form-inline form-order-change">
+                    <div class="form-order-change" data-pricecalc-endpoint="{% url "api-v1:orderposition-price_calc" organizer=order.event.organizer.slug event=order.event.slug pk=position.pk %}">
                         {% bootstrap_form_errors position.form %}
                         {% if position.custom_error %}
                             <div class="alert alert-danger">
                                 {{ position.custom_error }}
                             </div>
                         {% endif %}
-                        <p class="help-block">
-                            {% trans "Ticket secret:" %} {{ position.secret|slice:":12" }}…
-                        </p>
-                        <div class="radio">
-                            <label>
-                                <input name="{{ position.form.prefix }}-operation" type="radio" value=""
-                                        {% if not position.form.operation.value %}checked="checked"{% endif %}>
-                                {% trans "Keep unchanged" %}
-                            </label>
+                        <div class="row">
+                            <div class="col-sm-5 col-sm-offset-3">
+                                <strong>{% trans "Current value" %}</strong>
+                            </div>
+                            <div class="col-sm-4">
+                                <strong>{% trans "Change to" %}</strong>
+                            </div>
                         </div>
-                        <div class="radio">
-                            <label>
-                                <input name="{{ position.form.prefix }}-operation" type="radio" value="product"
-                                        {% if position.form.operation.value == "product" %}checked="checked"{% endif %}>
-                                {% trans "Change product to" %}
+                        <div class="row">
+                            <div class="col-sm-3">
+                                <strong>{% trans "Product" %}</strong>
+                            </div>
+                            <div class="col-sm-5">
+                                {{ position.item }}
+                                {% if position.variation %}
+                                    – {{ position.variation }}
+                                {% endif %}
+                            </div>
+                            <div class="col-sm-4">
                                 {% bootstrap_field position.form.itemvar layout='inline' %}
-                            </label>
-                            <label class="checkbox">
-                                {{ position.form.change_product_keep_price }}
-                                {% trans "Keep price the same" %}
-                            </label>
+                            </div>
                         </div>
+
                         {% if request.event.has_subevents %}
-                            <div class="radio">
-                                <label>
-                                    <input name="{{ position.form.prefix }}-operation" type="radio" value="subevent"
-                                            {% if position.form.operation.value == "subevent" %}checked="checked"{% endif %}>
-                                    {% trans "Change date to" context "subevent" %}
+                            <div class="row">
+                                <div class="col-sm-3">
+                                    <strong>{% trans "Date" context "subevent" %}</strong>
+                                </div>
+                                <div class="col-sm-5">
+                                    {{ position.subevent }}
+                                </div>
+                                <div class="col-sm-4">
                                     {% bootstrap_field position.form.subevent layout='inline' %}
-                                </label>
+                                </div>
                             </div>
                         {% endif %}
-                        <div class="radio">
-                            <label>
-                                <input name="{{ position.form.prefix }}-operation" type="radio" value="price"
-                                        {% if position.form.operation.value == "price" %}checked="checked"{% endif %}>
-                                {% trans "Change price to" %}
+
+                        <div class="row">
+                            <div class="col-sm-3">
+                                <strong>{% trans "Price" %}</strong>
+                            </div>
+                            <div class="col-sm-5">
+                                {{ position.price|money:request.event.currency }}<br>
+                                {% if position.tax_rate %}
+                                    <small>{% blocktrans trimmed with rate=position.tax_rate name=position.tax_rule.name %}
+                                        <strong>incl.</strong> {{ rate }}% {{ name }}
+                                    {% endblocktrans %}</small>
+                                {% endif %}
+                            </div>
+                            <div class="col-sm-4 field-container">
                                 {% bootstrap_field position.form.price addon_after=request.event.currency layout='inline' %}
-                                {% if position.apply_tax %}
-                                    {% if position.item.tax_rule and not position.item.tax_rule.price_includes_tax %}
-                                        {% blocktrans trimmed with rate=position.item.tax_rule.rate name=position.item.tax_rule.name %}
-                                            <strong>plus</strong> {{ rate }}% {{ name }}
-                                        {% endblocktrans %}
-                                    {% elif position.item.tax_rule %}
-                                        {% blocktrans trimmed with rate=position.item.tax_rule.rate name=position.item.tax_rule.name %}
-                                            <strong>incl.</strong> {{ rate }}% {{ name }}
-                                        {% endblocktrans %}
-                                    {% endif %}
-                                {% else %}
-                                    {% trans "no taxes apply" %}
-                                {% endif %}
-                            </label>
+                                <small><strong>{% trans "including all taxes" %}</strong></small>
+                            </div>
                         </div>
-                        <div class="radio">
-                            <label>
-                                <input name="{{ position.form.prefix }}-operation" type="radio" value="split"
-                                        {% if position.form.operation.value == "split" %}checked="checked"{% endif %}>
-                                {% trans "Split into new order" %}
-                            </label>
-                        </div>
-                        <div class="radio">
-                            <label>
-                                <input name="{{ position.form.prefix }}-operation" type="radio" value="secret"
-                                        {% if position.form.operation.value == "secret" %}checked="checked"{% endif %}>
-                                {% trans "Generate a new secret" %}
-                            </label>
-                        </div>
-                        <div class="radio">
-                            <label>
-                                <input name="{{ position.form.prefix }}-operation" type="radio" value="cancel"
-                                        {% if position.form.operation.value == "cancel" %}checked="checked"{% endif %}>
-                                {% trans "Cancel position" %}
-                                {% if position.addons.exists %}
-                                    <em class="text-danger">
-                                        {% trans "Removing this position will also remove all add-ons to this position." %}
-                                    </em>
-                                {% endif %}
-                            </label>
+
+                        <div class="row">
+                            <div class="col-sm-3">
+                                <strong>{% trans "Ticket secret" %}</strong>
+                            </div>
+                            <div class="col-sm-5">
+                                {{ position.secret|slice:":12" }}…
+                            </div>
+                            <div class="col-sm-4">
+                                {% bootstrap_field position.form.operation_secret layout='inline' %}
+                            </div>
                         </div>
+
+                        {% bootstrap_field position.form.operation_cancel layout='inline' %}
+                        {% bootstrap_field position.form.operation_split layout='inline' %}
+                        {% if position.addons.exists %}
+                            <em class="text-danger">
+                                {% trans "Removing this position will also remove all add-ons to this position." %}
+                            </em>
+                        {% endif %}
                     </div>
                 </div>
             </div>
diff --git a/src/pretix/control/views/orders.py b/src/pretix/control/views/orders.py
index d1d46c0520..a500d30b75 100644
--- a/src/pretix/control/views/orders.py
+++ b/src/pretix/control/views/orders.py
@@ -1240,7 +1240,11 @@ class OrderChange(OrderView):
                 return False
 
             try:
-                if p.form.cleaned_data['operation'] == 'product':
+                if p.form.cleaned_data['operation_cancel']:
+                    ocm.cancel(p)
+                    continue
+
+                if p.form.cleaned_data['itemvar']:
                     if '-' in p.form.cleaned_data['itemvar']:
                         itemid, varid = p.form.cleaned_data['itemvar'].split('-')
                     else:
@@ -1251,16 +1255,19 @@ class OrderChange(OrderView):
                         variation = ItemVariation.objects.get(pk=varid, item=item)
                     else:
                         variation = None
-                    ocm.change_item(p, item, variation, keep_price=p.form.cleaned_data['change_product_keep_price'])
-                elif p.form.cleaned_data['operation'] == 'price':
-                    ocm.change_price(p, p.form.cleaned_data['price'])
-                elif p.form.cleaned_data['operation'] == 'subevent':
+                    if item != p.item or variation != p.variation:
+                        ocm.change_item(p, item, variation)
+
+                if self.request.event.has_subevents and p.form.cleaned_data['subevent'] and p.form.cleaned_data['subevent'] != p.subevent:
                     ocm.change_subevent(p, p.form.cleaned_data['subevent'])
-                elif p.form.cleaned_data['operation'] == 'cancel':
-                    ocm.cancel(p)
-                elif p.form.cleaned_data['operation'] == 'split':
+
+                if p.form.cleaned_data['price'] != p.price:
+                    ocm.change_price(p, p.form.cleaned_data['price'])
+
+                if p.form.cleaned_data['operation_split']:
                     ocm.split(p)
-                elif p.form.cleaned_data['operation'] == 'secret':
+
+                if p.form.cleaned_data['operation_secret']:
                     ocm.regenerate_secret(p)
 
             except OrderError as e:
diff --git a/src/pretix/static/pretixcontrol/js/ui/orderchange.js b/src/pretix/static/pretixcontrol/js/ui/orderchange.js
new file mode 100644
index 0000000000..9a6484516e
--- /dev/null
+++ b/src/pretix/static/pretixcontrol/js/ui/orderchange.js
@@ -0,0 +1,51 @@
+/*global $, gettext*/
+$(function () {
+    // Question view
+    if (!$(".form-order-change").length) {
+        return;
+    }
+    $(".form-order-change").each(function () {
+        var url = $(this).attr("data-pricecalc-endpoint");
+        var $itemvar = $(this).find("[name*=itemvar]");
+        var $subevent = $(this).find("[name*=subevent]");
+        var $price = $(this).find("[name*=price]");
+        var update_price = function () {
+            console.log(url);
+            var itemvar = $itemvar.val();
+            var item = null;
+            var variation = null;
+            if (itemvar.indexOf("-")) {
+                item = parseInt(itemvar.split("-")[0]);
+                variation = parseInt(itemvar.split("-")[1]);
+            } else {
+                item = parseInt(itemvar);
+            }
+            $price.closest(".field-container").append("<small class=\"loading-indicator\"><span class=\"fa fa-cog fa-spin\"></span> " +
+                gettext("Calculating default price…") + "</small>");
+            $.ajax(
+                {
+                    'type': 'POST',
+                    'url': url,
+                    'headers': {'X-CSRFToken': $("input[name=csrfmiddlewaretoken]").val()},
+                    'data': JSON.stringify({
+                        'item': item,
+                        'variation': variation,
+                        'subevent': $subevent.val(),
+                        'locale': $("body").attr("data-pretixlocale"),
+                    }),
+                    'contentType': "application/json",
+                    'success': function (data) {
+                        $price.val(data.gross_formatted);
+                        $price.closest(".field-container").find(".loading-indicator").remove();
+                    },
+                    // 'error': …
+                    'context': this,
+                    'dataType': 'json',
+                    'timeout': 30000
+                }
+            );
+        };
+        $itemvar.on("change", update_price);
+        $subevent.on("change", update_price);
+    });
+});
diff --git a/src/pretix/static/pretixcontrol/scss/_forms.scss b/src/pretix/static/pretixcontrol/scss/_forms.scss
index c917b50e31..ecf34376e7 100644
--- a/src/pretix/static/pretixcontrol/scss/_forms.scss
+++ b/src/pretix/static/pretixcontrol/scss/_forms.scss
@@ -407,6 +407,12 @@ table td > .checkbox input[type="checkbox"] {
   }
 }
 
+.form-order-change {
+  .row {
+    padding: 5px 0;
+  }
+}
+
 @media(max-width: $screen-xs-max) {
   .nameparts-form-group {
     display: block;
@@ -455,3 +461,4 @@ table td > .checkbox input[type="checkbox"] {
     }
   }
 }
+
diff --git a/src/tests/api/test_orders.py b/src/tests/api/test_orders.py
index 943db7f7d1..e660ec8b8c 100644
--- a/src/tests/api/test_orders.py
+++ b/src/tests/api/test_orders.py
@@ -2798,3 +2798,222 @@ def test_order_resend_link(token_client, organizer, event, order):
         ), format='json', data={}
     )
     assert resp.status_code == 400
+
+
+@pytest.mark.django_db
+def test_orderposition_price_calculation(token_client, organizer, event, order, item):
+    op = order.positions.first()
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orderpositions/{}/price_calc/'.format(organizer.slug, event.slug, op.pk),
+        data={
+        }
+    )
+    assert resp.status_code == 200
+    assert resp.data == {
+        'gross': Decimal('23.00'),
+        'gross_formatted': '23.00',
+        'name': '',
+        'net': Decimal('23.00'),
+        'rate': Decimal('0.00'),
+        'tax': Decimal('0.00')
+    }
+
+
+@pytest.mark.django_db
+def test_orderposition_price_calculation_item_with_tax(token_client, organizer, event, order, item, taxrule):
+    item2 = event.items.create(name="Budget Ticket", default_price=23, tax_rule=taxrule)
+    op = order.positions.first()
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orderpositions/{}/price_calc/'.format(organizer.slug, event.slug, op.pk),
+        data={
+            'item': item2.pk
+        }
+    )
+    assert resp.status_code == 200
+    assert resp.data == {
+        'gross': Decimal('23.00'),
+        'gross_formatted': '23.00',
+        'name': '',
+        'net': Decimal('19.33'),
+        'rate': Decimal('19.00'),
+        'tax': Decimal('3.67')
+    }
+
+
+@pytest.mark.django_db
+def test_orderposition_price_calculation_item_with_variation(token_client, organizer, event, order):
+    item2 = event.items.create(name="Budget Ticket", default_price=23)
+    var = item2.variations.create(default_price=12, value="XS")
+    op = order.positions.first()
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orderpositions/{}/price_calc/'.format(organizer.slug, event.slug, op.pk),
+        data={
+            'item': item2.pk,
+            'variation': var.pk
+        }
+    )
+    assert resp.status_code == 200
+    assert resp.data == {
+        'gross': Decimal('12.00'),
+        'gross_formatted': '12.00',
+        'name': '',
+        'net': Decimal('12.00'),
+        'rate': Decimal('0.00'),
+        'tax': Decimal('0.00')
+    }
+
+
+@pytest.mark.django_db
+def test_orderposition_price_calculation_subevent(token_client, organizer, event, order, subevent):
+    item2 = event.items.create(name="Budget Ticket", default_price=23)
+    op = order.positions.first()
+    op.subevent = subevent
+    op.save()
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orderpositions/{}/price_calc/'.format(organizer.slug, event.slug, op.pk),
+        data={
+            'item': item2.pk,
+            'subevent': subevent.pk
+        }
+    )
+    assert resp.status_code == 200
+    assert resp.data == {
+        'gross': Decimal('23.00'),
+        'gross_formatted': '23.00',
+        'name': '',
+        'net': Decimal('23.00'),
+        'rate': Decimal('0.00'),
+        'tax': Decimal('0.00')
+    }
+
+
+@pytest.mark.django_db
+def test_orderposition_price_calculation_subevent_with_override(token_client, organizer, event, order, subevent):
+    item2 = event.items.create(name="Budget Ticket", default_price=23)
+    se2 = event.subevents.create(name="Foobar", date_from=datetime.datetime(2017, 12, 27, 10, 0, 0, tzinfo=UTC))
+    se2.subeventitem_set.create(item=item2, price=12)
+    op = order.positions.first()
+    op.subevent = subevent
+    op.save()
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orderpositions/{}/price_calc/'.format(organizer.slug, event.slug, op.pk),
+        data={
+            'item': item2.pk,
+            'subevent': se2.pk
+        }
+    )
+    assert resp.status_code == 200
+    assert resp.data == {
+        'gross': Decimal('12.00'),
+        'gross_formatted': '12.00',
+        'name': '',
+        'net': Decimal('12.00'),
+        'rate': Decimal('0.00'),
+        'tax': Decimal('0.00')
+    }
+
+
+@pytest.mark.django_db
+def test_orderposition_price_calculation_voucher_matching(token_client, organizer, event, order, subevent, item):
+    item2 = event.items.create(name="Budget Ticket", default_price=23)
+    q = event.quotas.create(name="Quota")
+    q.items.add(item)
+    q.items.add(item2)
+    voucher = event.vouchers.create(price_mode="set", value=15, quota=q)
+    op = order.positions.first()
+    op.voucher = voucher
+    op.save()
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orderpositions/{}/price_calc/'.format(organizer.slug, event.slug, op.pk),
+        data={
+            'item': item2.pk,
+        }
+    )
+    assert resp.status_code == 200
+    assert resp.data == {
+        'gross': Decimal('15.00'),
+        'gross_formatted': '15.00',
+        'name': '',
+        'net': Decimal('15.00'),
+        'rate': Decimal('0.00'),
+        'tax': Decimal('0.00')
+    }
+
+
+@pytest.mark.django_db
+def test_orderposition_price_calculation_voucher_not_matching(token_client, organizer, event, order, subevent, item):
+    item2 = event.items.create(name="Budget Ticket", default_price=23)
+    q = event.quotas.create(name="Quota")
+    q.items.add(item)
+    voucher = event.vouchers.create(price_mode="set", value=15, quota=q)
+    op = order.positions.first()
+    op.voucher = voucher
+    op.save()
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orderpositions/{}/price_calc/'.format(organizer.slug, event.slug, op.pk),
+        data={
+            'item': item2.pk,
+        }
+    )
+    assert resp.status_code == 200
+    assert resp.data == {
+        'gross': Decimal('23.00'),
+        'gross_formatted': '23.00',
+        'name': '',
+        'net': Decimal('23.00'),
+        'rate': Decimal('0.00'),
+        'tax': Decimal('0.00')
+    }
+
+
+@pytest.mark.django_db
+def test_orderposition_price_calculation_net_price(token_client, organizer, event, order, subevent, item, taxrule):
+    taxrule.price_includes_tax = False
+    taxrule.save()
+    item2 = event.items.create(name="Budget Ticket", default_price=10, tax_rule=taxrule)
+    op = order.positions.first()
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orderpositions/{}/price_calc/'.format(organizer.slug, event.slug, op.pk),
+        data={
+            'item': item2.pk,
+        }
+    )
+    assert resp.status_code == 200
+    assert resp.data == {
+        'gross': Decimal('11.90'),
+        'gross_formatted': '11.90',
+        'name': '',
+        'net': Decimal('10.00'),
+        'rate': Decimal('19.00'),
+        'tax': Decimal('1.90')
+    }
+
+
+@pytest.mark.django_db
+def test_orderposition_price_calculation_reverse_charge(token_client, organizer, event, order, subevent, item, taxrule):
+    taxrule.price_includes_tax = False
+    taxrule.eu_reverse_charge = True
+    taxrule.home_country = Country('DE')
+    taxrule.save()
+    order.invoice_address.is_business = True
+    order.invoice_address.vat_id = 'ATU1234567'
+    order.invoice_address.vat_id_validated = True
+    order.invoice_address.country = Country('AT')
+    order.invoice_address.save()
+    item2 = event.items.create(name="Budget Ticket", default_price=10, tax_rule=taxrule)
+    op = order.positions.first()
+    resp = token_client.post(
+        '/api/v1/organizers/{}/events/{}/orderpositions/{}/price_calc/'.format(organizer.slug, event.slug, op.pk),
+        data={
+            'item': item2.pk,
+        }
+    )
+    assert resp.status_code == 200
+    assert resp.data == {
+        'gross': Decimal('10.00'),
+        'gross_formatted': '10.00',
+        'name': '',
+        'net': Decimal('10.00'),
+        'rate': Decimal('0.00'),
+        'tax': Decimal('0.00')
+    }
diff --git a/src/tests/api/test_permissions.py b/src/tests/api/test_permissions.py
index d852f93a04..aee4692843 100644
--- a/src/tests/api/test_permissions.py
+++ b/src/tests/api/test_permissions.py
@@ -26,6 +26,7 @@ event_permission_sub_urls = [
     ('get', 'can_view_orders', 'orders/', 200),
     ('get', 'can_view_orders', 'orderpositions/', 200),
     ('delete', 'can_change_orders', 'orderpositions/1/', 404),
+    ('post', 'can_change_orders', 'orderpositions/1/price_calc/', 404),
     ('get', 'can_view_vouchers', 'vouchers/', 200),
     ('get', 'can_view_orders', 'invoices/', 200),
     ('get', 'can_view_orders', 'invoices/1/', 404),
diff --git a/src/tests/base/test_orders.py b/src/tests/base/test_orders.py
index 59dba7fb18..8033ed3bdb 100644
--- a/src/tests/base/test_orders.py
+++ b/src/tests/base/test_orders.py
@@ -611,49 +611,27 @@ class OrderChangeManagerTests(TestCase):
         self.op1.refresh_from_db()
         self.order.refresh_from_db()
         assert self.op1.subevent == se2
-        assert self.op1.price == 12
+        assert self.op1.price == Decimal('23.00')
         assert self.order.total == self.op1.price + self.op2.price
 
-    def test_change_subevent_reverse_charge(self):
-        self._enable_reverse_charge()
+    def test_change_subevent_with_price_success(self):
         self.event.has_subevents = True
         self.event.save()
         se1 = self.event.subevents.create(name="Foo", date_from=now())
         se2 = self.event.subevents.create(name="Bar", date_from=now())
-        SubEventItem.objects.create(subevent=se2, item=self.ticket, price=10.7)
+        SubEventItem.objects.create(subevent=se2, item=self.ticket, price=12)
         self.op1.subevent = se1
         self.op1.save()
         self.quota.subevent = se2
         self.quota.save()
 
         self.ocm.change_subevent(self.op1, se2)
+        self.ocm.change_price(self.op1, Decimal('12.00'))
         self.ocm.commit()
         self.op1.refresh_from_db()
         self.order.refresh_from_db()
         assert self.op1.subevent == se2
-        assert self.op1.price == Decimal('10.00')
-        assert self.op1.tax_value == Decimal('0.00')
-        assert self.order.total == self.op1.price + self.op2.price
-
-    def test_change_subevent_net_price(self):
-        self.event.has_subevents = True
-        self.event.save()
-        se1 = self.event.subevents.create(name="Foo", date_from=now())
-        se2 = self.event.subevents.create(name="Bar", date_from=now())
-        self.tr7.price_includes_tax = False
-        self.tr7.save()
-        SubEventItem.objects.create(subevent=se2, item=self.ticket, price=10)
-        self.op1.subevent = se1
-        self.op1.save()
-        self.quota.subevent = se2
-        self.quota.save()
-
-        self.ocm.change_subevent(self.op1, se2)
-        self.ocm.commit()
-        self.op1.refresh_from_db()
-        self.order.refresh_from_db()
-        assert self.op1.subevent == se2
-        assert self.op1.price == Decimal('10.70')
+        assert self.op1.price == Decimal('12.00')
         assert self.order.total == self.op1.price + self.op2.price
 
     def test_change_subevent_sold_out(self):
@@ -680,14 +658,14 @@ class OrderChangeManagerTests(TestCase):
 
     def test_change_item_keep_price(self):
         p = self.op1.price
-        tv = self.op1.tax_value
-        self.ocm.change_item(self.op1, self.shirt, None, keep_price=True)
+        self.ocm.change_item(self.op1, self.shirt, None)
         self.ocm.commit()
         self.op1.refresh_from_db()
         self.order.refresh_from_db()
         assert self.op1.item == self.shirt
         assert self.op1.price == p
-        assert self.op1.tax_value == tv
+        assert self.op1.tax_value == Decimal('3.67')
+        assert self.op1.tax_rule == self.shirt.tax_rule
 
     def test_change_item_success(self):
         self.ocm.change_item(self.op1, self.shirt, None)
@@ -695,36 +673,23 @@ class OrderChangeManagerTests(TestCase):
         self.op1.refresh_from_db()
         self.order.refresh_from_db()
         assert self.op1.item == self.shirt
-        assert self.op1.price == self.shirt.default_price
+        assert self.op1.price == Decimal('23.00')
         assert self.op1.tax_rate == self.shirt.tax_rule.rate
         assert round_decimal(self.op1.price * (1 - 100 / (100 + self.op1.tax_rate))) == self.op1.tax_value
         assert self.order.total == self.op1.price + self.op2.price
 
-    def test_change_item_net_price_success(self):
-        self.tr19.price_includes_tax = False
-        self.tr19.save()
+    def test_change_item_with_price_success(self):
         self.ocm.change_item(self.op1, self.shirt, None)
+        self.ocm.change_price(self.op1, Decimal('12.00'))
         self.ocm.commit()
         self.op1.refresh_from_db()
         self.order.refresh_from_db()
         assert self.op1.item == self.shirt
-        assert self.op1.price == Decimal('14.28')
+        assert self.op1.price == Decimal('12.00')
         assert self.op1.tax_rate == self.shirt.tax_rule.rate
         assert round_decimal(self.op1.price * (1 - 100 / (100 + self.op1.tax_rate))) == self.op1.tax_value
         assert self.order.total == self.op1.price + self.op2.price
 
-    def test_change_item_reverse_charge(self):
-        self._enable_reverse_charge()
-        self.ocm.change_item(self.op1, self.shirt, None)
-        self.ocm.commit()
-        self.op1.refresh_from_db()
-        self.order.refresh_from_db()
-        assert self.op1.item == self.shirt
-        assert self.op1.price == Decimal('10.08')
-        assert self.op1.tax_rate == Decimal('0.00')
-        assert self.op1.tax_value == Decimal('0.00')
-        assert self.order.total == self.op1.price + self.op2.price
-
     def test_change_price_success(self):
         self.ocm.change_price(self.op1, Decimal('24.00'))
         self.ocm.commit()
@@ -738,7 +703,7 @@ class OrderChangeManagerTests(TestCase):
     def test_change_price_net_success(self):
         self.tr7.price_includes_tax = False
         self.tr7.save()
-        self.ocm.change_price(self.op1, Decimal('10.00'))
+        self.ocm.change_price(self.op1, Decimal('10.70'))
         self.ocm.commit()
         self.op1.refresh_from_db()
         self.order.refresh_from_db()
diff --git a/src/tests/control/test_orders.py b/src/tests/control/test_orders.py
index 8e28c8ef9d..35107ac205 100644
--- a/src/tests/control/test_orders.py
+++ b/src/tests/control/test_orders.py
@@ -935,11 +935,9 @@ class OrderChangeTests(SoupTest):
         self.client.post('/control/event/{}/{}/orders/{}/change'.format(
             self.event.organizer.slug, self.event.slug, self.order.code
         ), {
-            'op-{}-operation'.format(self.op1.pk): 'product',
             'op-{}-itemvar'.format(self.op1.pk): str(self.shirt.pk),
-            'op-{}-operation'.format(self.op2.pk): '',
-            'op-{}-itemvar'.format(self.op2.pk): str(self.ticket.pk),
-            'add-itemvar'.format(self.op2.pk): str(self.ticket.pk),
+            'op-{}-price'.format(self.op1.pk): str('12.00'),
+            'add-itemvar': str(self.ticket.pk),
         })
         self.op1.refresh_from_db()
         self.order.refresh_from_db()
@@ -965,14 +963,9 @@ class OrderChangeTests(SoupTest):
         self.client.post('/control/event/{}/{}/orders/{}/change'.format(
             self.event.organizer.slug, self.event.slug, self.order.code
         ), {
-            'op-{}-operation'.format(self.op1.pk): 'subevent',
             'op-{}-subevent'.format(self.op1.pk): str(se2.pk),
-            'op-{}-itemvar'.format(self.op1.pk): str(self.ticket.pk),
-            'op-{}-operation'.format(self.op2.pk): '',
-            'op-{}-itemvar'.format(self.op2.pk): str(self.ticket.pk),
-            'op-{}-subevent'.format(self.op2.pk): str(se1.pk),
-            'add-itemvar'.format(self.op2.pk): str(self.ticket.pk),
-            'add-subevent'.format(self.op2.pk): str(se1.pk),
+            'add-itemvar': str(self.ticket.pk),
+            'add-subevent': str(se1.pk),
         })
         self.op1.refresh_from_db()
         self.op2.refresh_from_db()
@@ -989,7 +982,7 @@ class OrderChangeTests(SoupTest):
             'op-{}-price'.format(self.op1.pk): '24.00',
             'op-{}-operation'.format(self.op2.pk): '',
             'op-{}-itemvar'.format(self.op2.pk): str(self.ticket.pk),
-            'add-itemvar'.format(self.op2.pk): str(self.ticket.pk),
+            'add-itemvar': str(self.ticket.pk),
         })
         self.op1.refresh_from_db()
         self.order.refresh_from_db()
@@ -1001,13 +994,8 @@ class OrderChangeTests(SoupTest):
         self.client.post('/control/event/{}/{}/orders/{}/change'.format(
             self.event.organizer.slug, self.event.slug, self.order.code
         ), {
-            'op-{}-operation'.format(self.op1.pk): 'cancel',
-            'op-{}-itemvar'.format(self.op1.pk): str(self.ticket.pk),
-            'op-{}-price'.format(self.op1.pk): str(self.op1.price),
-            'op-{}-operation'.format(self.op2.pk): '',
-            'op-{}-itemvar'.format(self.op2.pk): str(self.ticket.pk),
-            'op-{}-price'.format(self.op2.pk): str(self.op2.price),
-            'add-itemvar'.format(self.op2.pk): str(self.ticket.pk),
+            'op-{}-operation_cancel'.format(self.op1.pk): 'on',
+            'add-itemvar': str(self.ticket.pk),
         })
         self.order.refresh_from_db()
         assert self.order.positions.count() == 1
@@ -1017,12 +1005,6 @@ class OrderChangeTests(SoupTest):
         self.client.post('/control/event/{}/{}/orders/{}/change'.format(
             self.event.organizer.slug, self.event.slug, self.order.code
         ), {
-            'op-{}-operation'.format(self.op1.pk): '',
-            'op-{}-operation'.format(self.op2.pk): '',
-            'op-{}-itemvar'.format(self.op2.pk): str(self.ticket.pk),
-            'op-{}-price'.format(self.op2.pk): str(self.op2.price),
-            'op-{}-itemvar'.format(self.op1.pk): str(self.ticket.pk),
-            'op-{}-price'.format(self.op1.pk): str(self.op1.price),
             'add-itemvar': str(self.shirt.pk),
             'add-do': 'on',
             'add-price': '14.00',
@@ -1047,7 +1029,7 @@ class OrderChangeTests(SoupTest):
             self.event.organizer.slug, self.event.slug, self.order.code
         ), {
             'other-recalculate_taxes': 'on',
-            'add-itemvar'.format(self.op2.pk): str(self.ticket.pk),
+            'add-itemvar': str(self.ticket.pk),
             'op-{}-operation'.format(self.op1.pk): '',
             'op-{}-operation'.format(self.op2.pk): '',
             'op-{}-itemvar'.format(self.op2.pk): str(self.ticket.pk),