Depends on how many clutches your planning on.
I used a mini fridge last year and it worked great for one clutch.
Had I put a fan in it it would have been good for possibly 4 clutches.
Mini fridges are easy, just find a cheap or free broken used one, add 2 feet of 11x12 flexwatt heat tape, a good thermostat, a fan if using more than one shelf and your set.

This year we planned on more clutches, only had 2 take but we are using a true brand coke cooler with 3 shelves.
Works like a charm, $400 total into it thermostat and purchasing it and all.

http://www.ball-pythons.net/forums/s...ht=coke+cooler