There are a ton of them out there. If you search "what is my domain worth" there are a few with that exact match name.

The thing is ... they are not that reliable. They are all automated. Based on simple measurements like page rank, alexa rank, estimated traffic, age, etc. Then it just spits out a number based on some algorithm. And the range in between different sites sometimes varies drastically.

It does not take into consideration desirability, existing content, the niche, themes and plugins that come with it etc.

What someone is willing to pay for it will tell you the "real" value of it. Hope that helps

The answer = there is no such site.

A domain is only ever worth what someone is willing to pay for it. Nothing more. Nothing less.

Those domain valuation sites are not to be believed.