The local markets are way to disparate for the typical run-of-the-mill bike to build an accurate database. In SF, you can get a lot more for any decent 10 speed in running confdition than most other places. In fact, CL is a better venue than eBay for the more common stuff. A mid level nondescript Japanese bike will fetch more here than in, say, Beaver, Oklahoma.

The only time vintage bike prices seem to even out across the country is for collectible or otherwise special or noteworthy bikes.