I get my frozen rodents (rats and mice) from Rodentpro.com. I just received a 100 count of mice pinks for $37 (rodents and UPS 2nd day ground shipping).
I find their quality to be so much better than the local shop's who sell their own frozen mice. Rodentpro's all come with full milk bellies and are individually frozen, not this "block of pinkie bodies" that you have to break apart.
I'd check around in the Breeders/Dealers/Stores link above and look through all of the different rodent suppliers.