In that price range, Johnson's are good and so are the Ranco's. Hydrofarm make a on/off thermostat that is pretty good as well, and its like $25.74 with free shipping.
Here is a link to a post about the Hydrofam.
http://ball-pythons.net/forums/showt...8312-Hydrofarm
Here's a link to the site on Amazon.
http://www.amazon.com/Hydrofarm-MTPR...7301871&sr=8-2