The only other choice I would say you have, and mind you this in only in the meantime until you can spare that $75-110 for the good stuff, would be this:

Stay away from the rheostats and spend the $25-30 on a ZooMed ReptiTemp 500R thermostat. It's still a t-stat, albeit a low quality one, and it will work for you for a few months. Much better than the ESU or Alife ones, but you should still keep an eye on it and only use it until you can afford the better, reliable models.

Trust us, the one thing you should spend your money on is a good thermostat! Even if you have only one snake and you're just getting into keeping, you should still get at least a Johnson or Ranco. The ReptiTemp one will keep stable temps in the meantime, though.