You can get two of these Wildgame Innovations cameras from Amazon.com for $100.

They are great cameras. At $49.99 each this is a hell of a deal.

They take 8 AAs. Battery life is dependent on a lot of things, including temperature, whether you shoot video or take stills, IR night shots vs day shots, and size of image. Once I figured this out I have no probalem getting nearly a month worth of use and a few hundred pictures, from 8 AA batteries (I use Costco Brand multipacks)