I have no idea what eBay would really do but I would hope they would tell the buyer to pound sand.
There are 2 main types of buyers for these cards. One kind has no idea what they are doing. No good life lessons are free.
The other kind in the card flipper. They are hoping to get a card super cheap, cross it over and make a quick several bucks. I say screw these people. It is a gamble and if you lose it sucks and if you win that is awesome. This damn returning an item if you don't win is BS. Just my 2 cents.