Echoing what some have already said, the trading community is pretty darn good compared to various other hobbies/collector forums I've been on. The reddit system, in particular, works well by being strict enough to require timestamps and having bots to help root out banned/problem sellers. No system is perfect and there's always risk, but that helps greatly minimize it. There's also some great information in the sidebar of /r/mechmarket on how to protect yourself. FWIW, I've got over 200 trades and outside of a stolen package from my mailbox one time, it's been smooth sailing. I've also made quite a few friends/contacts who have been helpful along the way, which is a great bonus.