List them at $1 and see what happens, you might be surprised.
List them at $1, offer in your listing a healthy discount for multiple purchases, either off the price or off the shipping.
Some of these methods will result in slightly higher eBay FVF's, the amounts will not be big and you should be able to devise a way to have the buyers carry the cost.
Maybe buyers will end up accepting that those 25 & 50 cent cards are going to cost them an extra nickel or dime (or even a dollar?).
There are many other marketing techniques you can use to comply with the new rules while not chasing away your buyers...some of them will end up putting more money in your pocket.
Take this opportunity, some similar sellers will simply toss in the towel, this will give you an opportunity to free yourself of some competition.
Personally I don't "get" the concept of selling under a dollar items. The only way it seems feasible to me is if you are making all your profit on handling (fee avoidance) or depend on multiple item purchases which may still be viable if you offer incentives as in my second example.

"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915
- answering Trolls is voluntary, my policy is not to participate.