I've made two brooders out of old console stereos. You have to tear the guts out, replace the old fabric in front with screen, add the linoleum to the floor and attached a heatlamp at one end. They are great and really look like a piece of furniture in the house. I also had some leftover background for behind a fish tank, this what you can see on the back wall, and it's waterproof and easy to wipe down. The cost is less than $30, mainly for the light and linoleum. The top is already hinged, others might slide open. It is time consuming to remove the guts, but it's a good use to an old piece of furniture.
You can always find them free on Craigslist or the Freecycle in your area.
I'm currently working on converting a free baby crib to a brooder.