About $300k buys you a modest 2000 square foot house in a flyover state.
One thing I've thought about, when people talk about turning skyscrapers into housing, is that you don't actually have to use all of the space. Instead, figure out how many actual dwellings can be built given the amount of windows and utilities, and leave the rest of it empty or treat it like basement space.
Disclosure: Dweller of modest house in a flyover state.