Sean, if you don't mind barrels and doing your own washing
, many bulk food
importers give 'em away for free. They import
olives, pickles, peppers, feta cheese, etc. in USDA food-grade barrels ranging from 15-55 gallons, and then look for the cheapest way to get rid of them (give 'em away often) because "sanitizing" them and re-using them is not economically feasible.
processing labs (everything isn't digital yet) also often use tall 15-gallon containers that are USDA food
grade for innocuous things like bleach and fixer. These can be washed out and used for potable water
, again, they are simply put out with the trash.
Obviously the folks who take the time to soak, wash, clean, and ship these have to charge something--there's a lot of labor involved.
Still not the same as heavy-wall shaped tanks, just an alternative if you have space and time.