Destroying the value of all used stuff and risking people's lives
I buy used stuff on occasion, but things like batteries, servos, recievers, and stuff like that, it isn't worth it any more. I have been hosed a few times so I feel for you. Most are honest as you say, there are a few out there just wanting to unload junk. If you buy something at a swap meet, look it over good and make sure it works. If it isn't hooked up to work there, chances are it doesn't work for a reason. I don't even look at the small stuff anymore used. If you save a couple bucks on it used, it isn't worth it. I would rather pay the couple bucks and get new.