Google seem to have messed up geos a bit by listing local businesses theirselves, but on a personal note I don't click on just the ones that Google shows me, I would still rather look at a site which shows me a list of all the local businesses.
I wouldn't pay to much for it especially if .com instead of .co.uk assuming you wanted a UK town.
Based on being .com and having 3000 exacts I would pay no more than £150.