Just picked up one of these that I'll use for fermentation. It is food grade and is made to hold 90 lbs of dog food. I think it will work just fine to hold fermenting wort as well. I think that it will hold at least 12 gallons if not more. What do you think? $25 bucks. This is the same plastic vessel that AHBS and others sell for a lot more. The only drawback is the top is on an angle at the top.
Not sure if all Costco's will stock. these are made by a local san diego company so my thought is just here for now. They are on the Costco on Morena.