I started out on ebay because I didn't have any other leads. AT the time (three years ago), there were quite a few for sale, but there was also a LOT of overseas scamming going on, and everyone was warning about buying on that way. I'm fairly cautious about that kind of thing, so I used the ebay listings to find legitimate avionics shops in the US that were selling equipment that way, went to their ebay stores, and bought that way - I think mine came from Jolliet (J.A. ?). Anyway, once I found them on ebay, I called, and they said they could sell me a new one for only a couple hundred dollars more than the going used price, and it was a done deal!
just one experience,
Paul