Domainspade - I've been developing a domain appraisal system that's part machine part human - obviously it's in early beta, but the system takes into account many variables, mostly the usual suspects but I'm working on the formula so that it would cover more than your usual automatic systems. Here are some variables factored in:
-keyword frequency
-search popularity for keyword + long tail
-word count
-length in characters
-tld
-historical market value for main keyword
-advertiser bids for keywords
-brandability
So it's not a reseller valuation - more of a combination of reseller+end user potential. Obviously resellers will pay less, but some end users may pay much more. Domain valuation is a very subjective matter - what's gold for one is fool's gold in the eyes of another. I developed this system to add objectivity to my valuations, and to help me valuate names that I am interested in.
I think the system is on the right track - I can imagine wepark.com going for about $7,000 to the right domain/car/other parking service provider.
But as always, it's hard to find end users - you may have to hold on for >5 years. If you choose to sell to a reseller, expect marginal profits.
Anyway, domain valuation is hard, but it's also fun. Always take valuations with a grain of salt
Josh