Some of the cheapest cameras are the Stealth 35mm's

They taken very good pictures for the money. The problem with them is...you are always buying film, batteries and paying to have the film developed. You could buy rechargable batteries( they pay for themselves after a while) and to just get the pictures put on a CD instead of actual pictures. This is cheaper.

If you want to go digital, the Wildviews are about the cheapest.

The Wildview .3 megapixel does not put date or time on the photo. The flash is weak and only has a 15 ft. flash range ( most other cameras have at least a 30 flash range)

The Wildview 2.0 megapixel does put a date and time but still has the 15 ft. flash range. It does take better quality photos.

Both Wildviews have an ultra slow trigger time which will miss many shots. You just have to set it in areas where deer will linger a bit.