Most of us have limited budgets, and calories per dollar is all about maximizing the impact of those dollars. What foods will give you the most bang for your buck?
Not surprisingly, basic staples (rice, flour, dry beans and so on) do really well--which is why those kinds of things should form the foundation of your food storage.
Of course, you can't solely focus on dollars/calorie -- you'll end up with no protein, no vitamins, etc. -- and when you start getting into packaging for long term storage, prices quickly go up. But, calories per dollar it's a good thing to keep in mind when comparing like products, stretching your budget and making other purchasing decisions.
More on calories per dollar on SurvivalBlog - a good read.
Has anyone used calories per dollar in their buying decisions? Are there any other metrics you keep in mind when building up your food storage? Let the tribe know!