TOPIC: Negative fee field not working when event price is zero

I have opened a ticket but maybe someone has found a workaround to this issue:

We are a ski club offering full packages and land only packages for our trips. Last year, we set up a our trips with a zero price in the event price area of the Discounts & Fees tab, then used fields to have the user select their trip and the applicable discount.

However, now I can't apply a negative fee field to trips set up like this...the negative numbers only work if the event price field is not zero.

If that's the case, then it means I have to set up additional fields to reprice the trip properly. UGH. Any ideas?