[looki]

>I'm guessing you pay significantly more for food at these local places than you would at a big box grocery store.

I think you have a very wrong picture of what the GP is talking about, since this is not really the case at all. We're not talking about NY-style bodegas here. In Germany for example, cut-throat discount stores like Aldi that constantly try to lower the price floor for groceries are ubiquitous and can definitely be found in dense neighborhoods. Come to think of it, a while ago I read that they started building apartment buildings with a store integrated in the ground floor because that concept works well for them.

[matkoniecz]

Yeah, I have hilariously expensive convenience shop at ground floor of my apartment block. As bonus quality of products is low.

Twice the distance, 20m away there is another overpriced convenience shop but with a better quality.

I shop in supermarket about 250m away on ground floor of another apartment block that has quite good prices, good enough that it is not worth time and other costs to shop further away for many products.