Calories per Dollar.

It depends. I live in the middle (actually, on the northwest side) of a very large city. Our neighborhood is by no means fancy; the public high school a block away has the following stats:

95.2% were low income Students. 16.8% were Special Education Students. 19.2% were Limited English Learners.

But within a 5 - 10 minute walk, there’s one good-sized supermarket, probably a couple dozen dozen smaller grocery stores that sell fresh dairy, produce, and/or meat, and a few bakeries. One can buy just about any ordinary grocery item, and quite a few out-of-the-ordinary ones; we have halal butchers, Peruvian beans, several kinds of fresh steaming tortillas, etc. This is certainly not a food desert, and prices are comparable to just about anywhere - and much better than other local chain supermarkets in fancier neighborhoods (with comparable quality) for many items. The neighborhood is served by one main train line and several bus lines.

So yeah, at least some of the time, it’s quite possible to buy fresh produce, meat, etc. in a not-fancy urban neighborhood.

That’s a reasonable guess, but it depends on your potato prices. A pound of potatoes has 400 calories. You’d need 4 lbs of potatoes to equal one package of pasta (which has 1600 calories.) At the cheapie supermarkets by where I live, a pound of the least expensive pasta is usually cheaper than a pound of the least expensive potatoes, but it’s close.