Order it from one of the online brewing supply sites? Are you interested in a plug and play unit like a few of these from Midwest or one that must be built up electrically like the STC1000s on ebay? BTW, digital is much better than analog.
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.