I second Jason on this to the extent that you should not skimp on equipment. Really, the welfare of your snake is worth the (negligible) extra investment.
However, electonics circuit building and micro-controllers, is a hobby of mine. I haven't compared the circuit and components of the Hydrofarm against other non-proportional thermostats, but from my understanding it's doubtful that the Hydrofarm uses components or a circuit design of any significant lesser quality than that of Johnsnon or Ranco. I may prove myself wrong upon further analysis, but in my opinion the Johnson and Ranco are overpriced for non-proportional thermostats. When you're at the price point of a Johnson or Ranco, you might as well shell out the extra coin for a Herpstat which is proportional, tried, and tested.
If you're in a pinch, or need something temporary while you wait for your Herpstat to be built and shipped (I'm looking at you Bean Farm), get the Hydrofarm (I've done this). If you want to put non-proportional back ups in line with your proportional thermostats (as recommended by Herpstat), at this point I would recommend the Hydrofarm over the other non-proportional thermostats.