Most transactions here go very smoothly. If a buyer has 0-2 posts, I would be reluctant selling him any high priced item. I dont care as much how much feedback they have, but they should be a long standing member here. For large transactions, I would often like to have a phone number. Honestly, I have sold a bunch on Craigslist also. Call me paranoid, but even that is not safe. You can get robbed, or be given fake 100 bills. Besides you have to go through the hassle of meeting up with someone.
Fortunately, In selling and buying a bunch of stuff here, I have not had a bad experience, all excellent, and one just O.K. (a little annoying, and that was because I ignored my instinct) and the annoying one was with an established member with a bunch of feedback. so go figure.