Well if you go into your Paypal transaction history you can file a dispute about it and get the money back, unless you gifted it in which case he's got away with it unfortunately.
There's nothing we can do aside from ban the users found to be scamming people, the rules do state that the responsibility of sales rests with those involved, not the forums admin or moderation team.
Hopefully you'll be able to get the cash back. We'd have appreciated this feedback a little sooner though, he managed to scam someone else in the mean time and was reported 3 times, as well as twice under a different username. Needless to say, he won't be seen on here again any time soon...