Well for that price your choices are certainly going to be limited. If you can stretch your budget just a little more say to $150 or so you have more options.
For the $100 range you really only have a couple of choices (1) Wildview .3MP and (2) the Moultrie Game Spy.

For $150 you can probably pick up (1) Moultrie 200 (2) Wildview 2.0MP (3) Bushnell (4) Stealth WD-2. Of the ones listed the Stealth seems to be getting the best reviews.

Check out www.chaingame.com for more in depth reviews.