I happened to see a new website WebsiteOutlook.com which gives feedback on the possible evaluation of websites based on current traffic trends. Basically it gets the traffic data from Alexa and other search engines and makes a approximation of Google Adsense Revenues.
Based on this it also calculates the net worth of the domain name. But on the other hand the approximations are way off in terms of ad revenues, as the ad revenues are also based on the site content, country of the most users and ad platform.
But again it’s a nice tool to play around with to get a rough evaluation of your domain.
Or maybe you can boast to your wife..