I've bought and sold on there before, but it's kinda pizzing me off as of the last year or so. SOOO many spammers and scammers out there. If a deal looks too good, you have a right to be skeptical about it. Best bet is that if a phone number is listed, use it. If none is listed, then it's your call to email or not. It's particularly bad when selling something. I get emails with the subject line of something I listed for 2 days about a year ago and it's nothing but a "hey, I make money from home and so can you" thing - SPAM.
Buyer beware.