If you watch the sales you can get a 7qt chest freezer for around $160...perfectly holds 2 buckets which is one brew for me (10g).. The other one is a 12cf and holds 4 carboys, or I can even squeeze 2 carboys and 2 buckets in there..... That's 30 gallons of beer.
The controllers are expensive, yes. I leave home for days at a time and cannot be around to switch from heat to cool if necessary so I got the 2 stage ones.... You can save quite a bit with the single stage ones if you are around to keep an eye on them, or, you have a place to put them where ambient is relatively stable, just not what you need..... (Basment etc)