DNScoop checks with Alexa for the number of visitors to a site, a link to the Internet Archive and inbound links. This resource has decided my site is worth about $23,300.
Cubestat is another site that you might want to use to check out a site.It takes longer to run than the other two and that might be because it broke and stopped working, so alas! I have no idea what my site may be figuratively worth, not that I particularly care. However, when it comes to checking and evaluating sites, it may pay you to think laterally and try out of a few of this type of resource.