And whatever you do, DO NOT forward any portion of that check to the third party or to the buyer for any reason. If somethimg like that comes up in conversation, that is a very well known scam, and the check will subsequently bounce even after clearing through the bank via Reg E. I'd also suggest doing your best to check out the buyer to see if there are any obvious inconsistencies. Most scammers will not take the time to cover their tracks very well. If you have any doubts, cash in hand.

Good luck,
Craig