I've been using JumpStart tstats for years with no negative results.
That's not to say that Herpstat isn't a better product, it is. But I've never had a single problem with my JumpStarts or Big Apple tstat.
However, I just had a Ranco tstat fail on me. Not sure what it cost, I got it second hand with the enclosure. I know it's less than 5 years old.