Well to me looks like this forum dont care about the scammers this is the only problem of the board.
You could make plugin that uses paypal api & lr api to fund a "runegear" wallet with the verification of sms to the paypal phone number and lock the paypal account to one account & also lock it to one ip, then once person x sends funds to person y for a item then person y cannot cashout hes runegear balance for 3 days (Time for person x to make a disputes) and once person y cashes out his funds the admins take a 4% fee for beer.
This will stop the nigerian kids who use scampal because there mother doesnt feed them