I was burned on a Turntable sale. The seller used this trick to rob me, so I use it in my own defense. When I buy on ebay I only use my American Express card via PayPal.
1. PayPal claims to have a time limit on when a buyer can reverse you. American Express has a different time limit which is much longer.
2. If I reverse via American Express, they withdraw the funds form PayPal. PayPal has to then go get the money from the seller, I do not have to wait. Let them chase the guy around.
This was done to me, out of the blue the guy reverses on me way past the PayPal time limit guidelines. I beef to PayPal, and they tell me "sorry AMEX supersedes us."
When you use your AMEX card via PayPal you can see they don't like it. While you are going through the checkout screens they give you several songs and dances why you should not do this. This alone tells me they don't want to have to chase deadbeat sellers.