PayPal does not care because if they did they immediately would have fixed this, there also scammers the other way around....too long to explain but I have heard other stories of people given a different domain......so for PayPal to get on top of things they should get specialised in domains.....and till this industry won`t be as popular as others , the best thing to do is using Moniker Escrow.
If you want to trade $50 domains then you take the risks because there is nothing in the world that will give you back the domains , PayPal won`t absolutely do anything. It`s nothing new.