In January WalMart had the see through storage totes on clearence- $4 each. We bought two.
An aluminum pie pan (from Christmas), plastic light fixture ($2 at Lowes), used extension cord and a dimmer switch ($4 @ WalMart) and we have a nice brooder. With a hole saw we drilled a hole in each corner of the lid.
We drilled a small hole in the center for the wires and the small bolts for the fixture. We later added the dimmers switch, following the enclosed instructions for the switch. You can dim the 100 watt bulb to any temperature you want. We plan on adding a platform with hardware cloth to these later. See below photo. Will add more photos soon.