I've been trying to work out a way to organize neighborhood-level basic essentials storages on the cheap, so that people in that kind of situation can afford to take care of themselves until the power comes back on. Food is pretty easy, but water and sanitation are a bit more problematic so far.
[1] - just calories to make it over the hump, this is not health food. Ingredients are white flour, white sugar, vegetable oil, and some white rice for the people who can't do the wheat products. Add vitamin pills to prevent deficiency diseases and you can stay functional for a long time at about $0.30/day.