I think the communication line has to stay open, when someone sends a cheque it seems like forever for the part to come. I got a money order from WI and it took seven days to get here (Ontario, Canada) even if I sent the part the same day, It would take another week to get back to the buyer. Two weeks is a long time to wait. Usually, you can trust someone that has been a member for a while and makes regular posts, someone that has just signed up or has only made one post (to sell) I would think tiwce. Now you newbies don't hate!
I don't know what the answer is, do we have a rating system, a black list, I can see a problem with both but it seems more & more people are getting screwed.