Exact match US Geos (especially towns and cities) in .com: How are they appraised?

[the_poet]

How can you estimate the value of a US town/city in .com (the exact match, no additional keywords)? Among other factors (tourism, search volume, etc.), is there any sort of "graph" in which you have an average price for each level of population?

 

[999names]

My opinion Geos domains were worth a lot more before Google came out with GeoTargeting http://support.google.com/webmasters/bin/answer.py?hl=en&answer=62399