I think an easier method is just to track how many disputed orders a buyer has. Don't have to ID the order, or the transaction, just a little thing that says "this buyer has __ disputes in the past 30 days". As a seller if I see someone with 5 disputes in the past month or at least I have some ammo when it comes to arbitration/dispute through SR. Any seller with a reputation for delivering should be able to bring this to the table and have it considered in a dispute.This way it keeps transactions anonymous, but still leaves some transparency for a seller to decline an order or accept it. You can already check the user number to get an approximation of when that person joined so you know if they are a newb or have been hanging around for a while.