you might consider checking wine shops for some stuff. i find wineshops can be very old fashioned or have either very cheap or very overpriced stuff. planning to see if i can get a carboy brush at one for cheaper than my online HBS.
not an expert, but again i’d just try to consider if the type of bucket at lowe’s is food-safe, low pH safe(?) etc. maybe it is, im not sure.
My work has a foodservice operation and they get a few things like tahini, peanut butter, and honey in 5 gallon food grade buckets and they pile up so I get them for free. I have a couple dozen as they come in handy gardening etc. too.
I say this because if anyone is friendly with someone who runs or works in a restaurant, hotel, or school you can ask them if they can score you some.