There really is no such animal. The closest thing is the Uniden BCT-15, which runs anywhere between $219.95 to $269.95 delivered, depending on how good a shopper you are. There is no non-trunking scanner with alpha tags.
Radio shack has the Pro-163 that makes an ideal base scanner. Software is Win97, programming cable is RS part# 20-047. Alphatags for the bank and the frequency.Look around for a cheap used RadioShack Pro-2055, ebay always has some. They do have an issue with some radio's display going out but thats an easy fix. They are pretty decent recievers and they support 16 character alpha tags.
The PRO-92 & PRO-95 support alpha tagging and programming via computer (freeware), but also do trunking and have no related base models.