My favorit pet store is Pet Supplies Plus. Great prices. They have a brand of scoopable cat litter for $6.98 for a 40 pound bag. With 13 cats, that price is a godsend.
I buy my food at the vet's, but the have a lot to choose from and also good prices. I do buy my mouse food and toys there, carriers, new sisal scratching post (last week), the cats' favorite toys and dishes....etc... I really do spend more money on the cats then I do on myself. (and the mice!!!!!!!!!!!When I first got the mice, and needed to set up their homes, I got the mice for about $2 a piece and spent over $75 on STUFF!) And that was only for my first 3, when I started getting more mice, and more aquariums, I needed to get more STUFF !