Introduce a setting to show net prices (#415)

* Introduce a setting to show net prices in the frontend

* Show net prices in the backend as well

src/pretix/control/forms/event.py

@@ -158,6 +158,12 @@ class EventSettingsForm(SettingsForm):
         help_text=_("Show item details before presale has started and after presale has ended"),
         required=False
     )
+    display_net_prices = forms.BooleanField(
+        label=_("Show net prices instead of gross prices in the product list (not recommended!)"),
+        help_text=_("Independent of your choice, the cart will show gross prices as this the price that needs to be "
+                    "paid"),
+        required=False
+    )
     presale_start_show_date = forms.BooleanField(
         label=_("Show start date"),
         help_text=_("Show the presale start date before presale has started."),

src/pretix/control/forms/orders.py

@@ -59,7 +59,7 @@ class OrderPositionChangeForm(forms.Form):
     price = forms.DecimalField(
         required=False,
         max_digits=10, decimal_places=2,
-        label=_('New price')
+        label=_('New price (gross)')
     )
     operation = forms.ChoiceField(
         required=False,