When I first set up my glaze storage I purchased plastic paint buckets in various sizes, with matching with lids, for materials as I was not purchasing in large amounts. When I started going larger scale, I first got the promotional, thus lesser cost, 5-gallon buckets from home improvements stores, but found that the lids were difficult on and off, and would frequently break. I have since heard that the plastic has a lot of filler and will break down.
I now go to a restaurant supply store and purchase bain marie containers. They come in a multitude of sizes, are relatively inexpensive, are made of higher quality plastic, are much sturdier, and the lids go on and off very well. You can also see the material level through the side on many of them.
A bonus in the restaurant supply store is tools you may repurpose for pottery are all over the place.