Look for a cheap fridge or freezer on craigslist and put a controller on it. I bought both my fridge and my freezer for $50 each. You can make a controller cheaply with the STC-100 (controller $20, box $10, plugs $5 and wire and plug $4—OR you can steal an old PC power cord and use that. If you are anything like me, I have about fifty in the house), OR, if that is too scary, buy a RANCO from amazon (RANCO ETC-111000 Digital Cold Temperature Control NEW) for $53. While the RANCO is a single stage--that means it only heats or cools in one direction (you have to manually set it to go the other way). This really isn't a problem with a chest freezer. You either set it on heat and place a heat source in it during the winter and let the weather cool it, or plug the freezer in during the summer and let nature warm it. Either way, you have a temperature controlled fermenter for about $100. It might seem pricey at first, but after two or three bad batches of beer, it will pay for itself. Furthermore, there is nothing better than walking past your chamber every morning and seeing the controller read 64F and knowing that your fermenting beer is safe.