Did you pay via paypal? They are usually pretty good at this kind of thing. Also contact ebay. Since the return was in his listing he is obligated to uphold it, and ebay will crack down on him as well. For $900 I would explore every avenue including calling the local PD. Contact the seller again and let him know you are taking action, might scare him into refunding your money.

On another note, man I wish I had $900 to spend on a coin. I could get some primo boxes for that.

spiffy