ok so i bought a ranco etc thermostat for my new bps, two are using larger heat mats than the other, is it ok to just use a less expensive rheostat to fit in my budget? if not i will buy another ranco but i would like to limit spending for food for these guys and my other herps. im thinking of picking up a cheaper rheostat from zoo med instead of another 100 dollar thermostat, is this ok?