First of all, any seller that keeps thier feedback comments private is likely doing so for a reason...like to hide thier previous complaints against them that would make others avoid them. CROOK!
They're everywhere though. The wife was looking at a fancy handbag on eBay a while ago. Was listed as a "LV" whoich is kinda the slang for the pricey and Hollywood start Louis Vitton brnad bags. No body was bidding on this sellers "LV" stuff. She finally put in a bid. Shortly after, she got a e-mail from another ebayer telling her that the bag was a fake and a whle explanation. She contacted the seller who agreed to nullify the winning bid she had placed (the only bid actually). I decided to wait a day or so and found another of this seller's "LV" bags. I innocently asked if it was in deed a real Louis Vitton handbag. He responed that yes it was a "LV" bag. Again, I asked if it was a real Louis Vitton or a knock-off fake called a "LV". That was months ago and I'm still awaiting a response.
All comes down to if the deal seems too good to be true, it proberly is. and of course - buyer beware!