Paypal say "although we were charged a fee we waived it" I assume the fee is charged by the bank? Which paypal are charging $15 for?

I can see in the payment summary that it looks like the transaction fee didn't end up being payed.

This kind of scenario just makes buyers more likely to do the same thing and a seller unlikely to fight a chargeback if they are going to be out of pocket. I can understand if a buyer didn't receive their item but this is for a fraudulent use of a card.