Don't write it off just yet.
Please follow the recommendations Here
and to be on the extreme safe side, only buy from Team Members with > 500 posts that has been here over a year, and with Positive Feedback, or one of the dealers.
I don't want to start a flamewar about Team Members with 50 posts selling that have been here since 2001, I am merely posting the "typical demographic group" we have the least problems with.
(I am aware there are exceptions to the group listed above, but no "rule of thumb" is perfect!)
In practice, from what I have seen, we have about a 0.7% "failure rate" on deals, with 0.1% ending up with somebody totally screwed. The rest get worked out eventually with the mods working together with both parties to help make it right.