Current behavior:
Event registration forms can have fields with
'extra costs' - meaning that total event price is calculated as the
base fee plus extra costs depending on each registrant selections.
These extra costs can not currently be negative, this they can not
decrease the total price, only increase it.
Desired behavior:
Allow negative extra costs to implement certain complicated event pricing situations with discounts.
For example:
under 18 - $5 discount
bring a friend - $10 discount
Notes:
1) If the total price is negative, it will be processed as free registration, no refund will be issued.
2)
System will have no way of enforcing the correct selections. In the
example above, there will be no way of checking whether user is
actually under 18 or bringing a friend.
Dmitry Buterin, Chief Apricot