You know, it is not just huge Box stores that benefit from buying from places that sell things like wholesale fashion jewelry. It's true.
What the stores are doing is called "Buying in Bulk" and anywhere you look you will see that you can get a discount by buying multiple of the same item. We buy a HUGE percentage of our foods in bulk. The first two shelves in my pantry are filled with Tupperware containers filled with staples like flour, sugar, and rice.
Buying in bulk is not only good on the pocket book, but on the environment. You can buy two chicken breasts, each on a Styrofoam plate wrapped in plastic wrap, or buy a whole tray of them. You save on money and on the packaging!
Now of course, you cannot purchase "time sensitive" foods in bulk, but for staples, freezable or canned goods, it just makes more sense to buy bulk.