Going to post to give you a little more insight. Basically PlayerAuctions works as a middle man that holds the real life money. This way if a dispute is made against the seller from the buyer claiming that he did not receive the money or an unauthorized payment then PlayerAuctions handles the dispute and if the dispute goes in favor of the buyer then the money comes out of PlayerAuction's pocket, not yours. However, during the dispute process it is essential that you provide pictures of you trading the buyer and giving him his money, and proof that it is in fact the buyer. So when selling with PlayerAuctions make sure to document every aspect of the trade, so if a dispute is made you can combat it.
You can still get scammed with PlayerAuctions and people have before, but if you are very careful and document all trades there is no way that you can get scammed. PlayerAuctions is the safest way to sell GP with Paypal in my opinion.