What very cheap bulk food item can I subsist on alone?
Not that you’d really want to, but I once read a book which suggested that the only food you could live exclusively on was millet – based on accounts of people in eastern Europe, I think it was Ukraine, surviving on only millet for a couple of years during a war or a famine. I doubt that you could live for very much longer than that, as you wouldn’t be getting any vitamin C, for one thing.
