The dual controller from Midwest is $170.00, and the STC-1000 on eBay is $18.00 and free shipping. I built an STC-1000, with a few parts from the local Home Improvement store. I may have $35.00 in total invested, and I couldn't be happier with the quality of the controller.
I use a heating pad to heat my fermenter these days. I tried a Lasco 200 watt heater, and it was way too much heat. If you want to try a heating pad, make sure it does not have a built in timer.