In addition to the specific advice others have shared, the usual advice also applies. Try to get them to name a price first, be prepared to walk away if you don't like the price, and don't agree to a deal that you will regret when you wake up the next day.
Anything you'll be able to get above $500 will be a bonus.<p>I had hard time selling cool 1-letter domain so market for that stuff is quite specific.