The automatic value programs suck. You can try 5 and get completely different results.

Rank, Age, keywords, links and traffic determine worth. You never know who wants a domain. I sold one to a lady in Moscow a couple of months ago.
Did a free push at HOSTNHUB. The domain was parked. 10 dollar reg turned into 500 bucks. Domain name was under a year old and no website.

So you never know what a domain can sell for. If you owned social(dot) com and were selling, you could probably start shopping for a new fishing boat.