Obviously this guy has been ripped off here, i guess the only thing we can do is offer him some useful advice.
Scams like these as Jakg pointed out, are pretty common! And because they're so well known, you might be able to get your money back!
Firstly, how did you pay for it? If its PayPAL i think they have some sort of compensation regarding dodgey users scamming!
Or if you payed via Credit card, i think you might still even be able to get your money back, stating you had been scammed but I'm not sure!
And i guess the last option would be a cheque, if you sent a cheque go cancel it immediately!!
If you paid via postal order, well i think you're pretty screwed. Report it to ebay and all the authorities you know, get the phucker hammered.
The key to getting your money back here is to annoying the hell out of the people you used todo the transaction (paypal/bank/cc company)