They don't look cheap. This is the cheapest I could find:
http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=2790&is=REG
I have never used or seen one of these so let me get this straight. You hook your hot and cold to it, then set a fixed temp of say 70degrees, then turn it on and the water stays at that temp?
http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=2790&is=REG

I have never used or seen one of these so let me get this straight. You hook your hot and cold to it, then set a fixed temp of say 70degrees, then turn it on and the water stays at that temp?