alt Hacker NewsBodegas charge you a little bit more because a real human owner accepts the risk of serving a small community in exchange for being part of that community, and you pay that extra in order to make their existence possible.
Dollar Generals charge you a little bit more because a huge chain has driven out all the competition and you have no choice. The people who work there do not benefit from the extra you pay, and the owners are not members of the community.
There was no competition in many places dollar stores operate. They moved into those places specifically because they were underserved by larger retailers.