[Corin Stormhands]

That's why I'm worried, because if they try to pay me with a credit card, I was under the impression my account won't allow it.

Then regardless, that will be their problem. If they bid on the item, they are obligated by eBay to pay.

And I ~think~ Talon, that the premium for credit cards would be charged to the buyer.

[TalonDJ]

Those fees are charge to the people accepting the money so it makes sense to pass those costs on to the people making money. As far as I have seen Paypal does not charge you any extra to send money to someone via a card. But people that want to get money via paypal usually have to setup a paid account not a free one.