I always have them pay me through PayPal. I have my credit card account, checking account all linked to it for money transfer.
Are you buying from eBay or selling from eBay? If you buy stuff from eBay and pay through PayPal, it will come out of your credit card. See, PayPal is like the middle person that handles the transactions between you and the seller. PayPal will have your credit card account on file so when you do buy something and pay, your credit card will be charged via PayPal.
At least that's how I think of it.