I personally would buy a new one if your going to upgrade to a nice PVC and rhp setup, actually I would buy one anyways.
I agree with little tree guy, Herpstats are packed with features the competition doesn't have. They also hold a pretty steady temp instead of shutting on and off which will make your heating device last longer. For one snake get a Herpstat 1 or for 2 get the Herpstat 2. Spyder robotics does make a herpstat 1 basic and Herpstat intro models that are a little cheaper but they don't have the safety relay which IMO is a must for keeping a snake safe. They do make the Herpstat intro + that's a little cheaper that does have the safety relay but doesn't have the features of the others but the casing style is more for being built into a rack or something and only use 2 prong heating devices but would work for a cage. The other models besides the intros are designed to just set right on top of the cage or stand and actually are visually appealing. Vivarium Electronics by reptile basics makes a good thermostat with a saftey relay but you wouldn't want anything less then the ve-200 but it would be worth the little bit extra for the Herpstat 1. I own 2 ve-200, 1 ve-200d, 1 ve-300 and 1 Herpstat 6 and 1 Herpstat Pro (older version of 4) and I love them all and would buy any of them again but for feature per dollar you can't beat the Herpstat and it's not much more then a ve-200.
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