A thermostat is not something you want to skimp on.
http://ball-pythons.net/forums/showt...rmostat+failed
http://ball-pythons.net/forums/showt...mostat+failure
I use 4 of these in my room along with a Herpstat Pro. They are like 75 bucks and work GREAT.
http://ball-pythons.net/forums/showt...mostat+failure