iamfreelancer surely point out the dead lock situation...

2 parties engaging in this kind of transaction is very risky... wonder if anyone out there provide escrow service...It's niche if someone establish one especially for domain name :P off course with small amount of SO(service charge)

-Don't pay for something you haven't receive
-Don't give something if your'e not paid for it yet

If your location is near to the buyer, then the transaction should be easier cause you can deal face-to-face and on the spot with the person..

Maybe the registrar of the domain can play some minor role in the process of transaction. You can contact them and express the situation and the need for the registrar as 3rd party to make sure the confirmation of money transaction and domain transfer is running smoothly(although I haven't done such stuff)...