If you have a Wal-Mart near you they have them I cannot speak for how good they are. Considered buying one sometime ago but really do not have any call for one. Good Luck.
I use matfer tempering machines at work, air heated with a motor and wheel attachment. This is preferable over our Roband which is water heated.
Cost of the matfer is around $2000 with motor and wheel, or $1000 without, worth every **** cent!!!