We have an Amish settlement about an hours drive from here. They sell the 55 gallon barrels at the cheese factory for $5 or $10 and get snapped up quickly. If you are not there the day they set them out, you do not get one. DH and both sons are commercial industrial painters. I have more 5 gallon buckets than you can shake a stick at!
I picked up half a dozen 55 gal. drums at a dairy trucking site. They used food grade chemicals to cleanse the trucks down every night. They said they had to pay big bucks to have them handled as hazardous materials and removed. They were happy to send me on my way with them for free. It's been about 4 years since I lost my truck and access to that site again so I don't know if they are still free or not.
depends around here. i got one at a yard sale for $2 about a year ago but it didn't have the top with it. we have a brewery in Portsmouth that occasionally has the same barrels for free but you have to be quick to get them. they're used for the storing of ingredients used for the beer. i've seen on CraigsList the same barrels for about $20 with their lids and the 500 gallon tanks used around farms that have the metal cage going for about $75. i've been tempted to get one of the tanks and keep it behind my coop hooked up to a gutter system. but with the wet summers we've had i'm thinking i don't need to collect much water for storing.