Some manufactures have policies against selling on the internet. I would understand if they were a dealer, asking the serial number would spook them. The price though, seems extremely low (well below what a dealer can buy it for), and the guy presented himself as an end-user. Sound fishy to me. Anyone with time on their hands can easily bring up their rating and still be a slimeball waiting to score big, with high dollar amounts. You did the right thing, just be thankful you still have your hard earn money. I tell this to everyone, when making large dollar purchases on eBay, use a reputable escrow service... Don't be a victim!