The problem with not paying FF with PayPal is for sellers. Scammers grab the domain then claim "goods not received" and get refunded, so the seller loses the domain and gets no payment for it.
The only answer, as others have said already, is to not pay, but also not accept payment, by PP. It's a shame when escrow becomes a necessity for even the smallest transactions but it seems the only way.
Even when both parties are completely open and honest, PP has a habit of screwing up. I recently had three attempts at payment refunded and didn't succeed until the fourth. Without bothering to tell me, and accepting my payment instead of refusing it, PP wanted the seller's email "verifying" - a customer of theirs for years. They didn't just repay my money, I had to go and ask for it back. Of course, the seller was understandably fretful throughout, thinking I was trying to pull a scam. It took many hours to sort out and not until then could he relax.
That was when I made the decision never again to join in an auction when the payment method is stated as PP. Sorry, guys, that's one less bidder for some of your auctions. I wouldn't dream of accepting payment by PayPal, too many scams and cockups. So that's me out of NP auctions altogether.
Bearing in mind that PayPal have made lots of pretty weird decisions and held people's money, denying them access to it, on the flimsiest of excuses in the past, I am most loath to leave money in a PP account. I prefer not to use them at all.
It is very sad that the world's international banking system works in such a way as to make such vehicles the only ones available between some countries for ordinary citizens well into the twenty-first century.