Under primitive, emergency, or even just unfavorable conditions it is a lot easier to turn rice into something edible than it is for flour.
Boil water, add rice. It doesn't even have to be safe drinking water -- just boil it for a while longer. No electricity, only fire.
I would never buy some huge bag of flour like that but just was using that as an example of how a bulk wheat product was still fairly inexpensive. I love rice. I think a huge 40 lb bag of calrose was in the $30’s.