Several registrars and other firms do hand-appraisals of domains.  They do some statistical analysis on the domain name (is it .com or something else, how many characters is it, is it spelled properly), as well as a less precise assessment of how likable the domain is, which typically includes the sort of "comparable" search that I'd done (possibly with better data). 

None are free, but I wanted someone with a more educated opinion to give me some guidance.  I tried two of the services, GoDaddy.com and Sedo.com and will post the results when they come in.