Paypal protection? Give me a break. I know some sellers have sent the items, and later the buyers have claimed the package never arrived and Paypal have withdrawn the money from the sellers.
From that point -or if some sellers know somebody who has gone through that-, sellers will start sending everything overseas via registered mail -more expensive for the buyer-, or refusing to sell overseas altogether. That is very bad practice in my opinion, as even when you run a risk of having a buyer asking for a refund, you are better off the more bidders you have, genuine or not.
Furthermore, for things of low value, it is pointless to ask for a refund because Paypal always retain a given fee, say 30 or 40 bucks, so for many items you won't get any refund at all even if you never got what you paid for. I have had a couple of items never received and have never asked for a refund, as I don't think either that anybody would pretend they sent me something they didn't just to rip me 40 bucks off.