FWIW, buyer protection through Paypal is a crock of ****. If you use a credit card through Paypal, you can have your CC company cancel the charges. Paypal? They'll open an "investigation" then tell you all your money is gone.
I've had to use it once when somebody sold me fake concert tickets, and it was a piece of cake to get my money back. There was a short investigation for a couple weeks and then they credited back my money.
The only thing I've heard is that the seller can sometimes get screwed since Paypal will almost always side with the buyer.
So for instance if some idiot buyer bids on something that's clearly marked as non-working and didn't read the listing, they could force their way to a refund, and the seller has to deal with the hassle.
I suppose a seller could close the account linked to their Paypal, which would probably restrict the refund from being sent, but I can't imagine that happens very often. If the seller has good feedback, you can be pretty certain they won't pull any BS.