I'll give a practical example. If you got to a gas station near me, you can get a CR2032 battery for say 2 USD. If you got to a certain home decor/equipment store a mile away, you'll get 4 of these batteries for 1 USD. That's what, 8x more expensive for a relatively common product? Gas stations and convenience stores in my country routinely charge 500-1000% more for common products because, and here's the gist of it I'm sure for most store/chain owners, "why not"?