From prices I've seen when looking it up has been over priced in my opinion.
Have you looked at reptilebasics.com? thats where i ordered mine from, they have prices from $59-$140.. i've heard nothing but bad things about the cheap ones though.. they're usually used as a backup thermostat
I wouldn't use anything less than the johnson/ranco on/off t-stats. They run about $70. The cheaper ones can be unreliable, I wouldn't trust them with my snakes.