I'm very good at spotting scams, very tech saavy. The volume of scammers seems to have increased over the past few months. You MUST do your due diligence or there is a good chance you're gonna get screwed. Ask as many questions as reasonable, get phone numbers to discuss, etc. Check references.
I'm selling a pair of speakers now and just for kicks I put them on my local craiglist yesterday. Within 10 minutes I had two scammers - both well worded messages to me. I asked for phone numbers of both, for a quick chat, and neither responded again.
More than ever - be careful out there! If you're not comfortable, don't do it.