My cats like Tidy Cats litter. So I stick to that one brand, as I don't need to have 7 cats choosing to ignore the boxes due to a change in litter.
Target will have it on sale about every 6 weeks, for 28 cents per pound. I usually by 6 plastic tubs, 35 pounds each. It gets stored in the garage. Somehow I missed one sale and was running low. As in the only litter in the house was an open tub, about half full. I was getting panicky, then Target had another sale. Whew! Saved. I bought EIGHT tubs this last trip. 280 pounds. My little Honda was NOT happy on the short ride home.

I still don't understand why the plastic tubs (plastic is an oil product, right?) can cost less than the boxes.

We have yellow plastic tubs all over the place. Dad loves them for carrying fertilizer from the shed to his vegetable garden. And all his small tools go in yellow tubs to move from one project to the next. He uses them to bring in his dahlia bulbs (and others) for the winter, then to carry them out again in the Spring. No project gets completed in a day. So we have yellow litter tubs as lawn ornaments.