LOL, just remember, you opened the thermostat discussion!!
Buy cheap, get cheap. Do you really want a cheap unit to control temperatures that are critical to the life of your snake? Cheap ones are typically made from less expensive components, less precise in actual temperature control and more likely to fail.
On/Off thermostats like the round brown dial ones (even Ranco's) are usually designed around a mechanical relay. Mechanical relays can and do stick. Not nearly as bad if they stick in the off position, deadly if they stick on. Yes, not real common to stick on but DOES happen. I've seen dual Ranco setups for sale where the second thermostat is a failsafe for the first. Duh, would not even be available if there were not instances of one sticking full on.
The thermostats I prefer are proportional solid state ones. Programed to shut off on failure and post a visible error code in the display. Herpstat, Herpstat ND or Helix DBS1000 would be my choice for a single thermostat. If you have multiple cages Herpstat Pro is four individual thermostats bundled into one control box and ends up being significantly cheaper than four separate units.
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Thanks,
Dave Colling

www.rainbows-r-us-reptiles.com
0.1 Wife (WC and still very fiesty)
0.2 kids (CBB, a big part of our selective breeding program)
LOL, to many snakes to list, last count (02/01/2010):
42.61 BRB
27.40 BCI
And those are only the breeders 
lots.lots.lots feeder mice and rats 

