I made a misting/rain system for about that price.
Items needed (all found at Home Depot)
1. Pond pump - get one that has enough pressure to really move the water
2. 5 gallon bucket
3. Misting heads - I bought the ones on the curly tubes
4. Splitter - allows you to run more than one mister head
4. Tubing to get from the mist head to the splitter
5. Tubing to get from the pump to the splitter
Run tubing from pump to splitter and then hook misting heads. Hang the mist heads in your cage. I put them in the top corners. Place the pump in your bucket with treated water. Plug in and enjoy.
I also ran a tube and put a 1 gallon per hour drip head on it. Then when i run the water he has a place to go drink as well. I will post pictures tonight when I get home it is a really easy setup and works great. The mist heads also have on/off valves on them so you can control if you want both, one, or none on.