I am trying to find a site that has a downloadable list, or at the very least a screen scrape-able, list of percent modifiers for calculating cost of living between major US cities.

I have been to the BLS and spent a lot of time trying to find some "modifier" value list based upon standard CPI values, but I can find no such beast, and what is there is really not useful for doing the conversions.

Does anybody know of a website that has a list of values one could use to perform calcs to determine the cost of living between metropolitan areas?

ACCR does a good job of this, they charge for the datasets but pricing is reasonable ($95/quarter). http://www.coli.org/

Of course it will be necessary to update your dataset frequently so it represents current prices. Also there will be variations depending upon rental, home ownership, etc.

You can also use the free BLS CPI data, but it only encompasses a relatively small number of cities.

"it only encompasses a relatively small number of cities" is putting it kindly. One would think with all the money they pour into these organizations, they might pay someone to do the calcs for more than 15+ some odd metro areas.

Thanks for the vendor link. I'll check them out.