A single packaged slice of banana bread from the convenience store has you on the short side of economies of scale, twice over.

A banana bread loaf from a grocery store will cost around $4, for eight of those slices. If you buy the mix and make it yourself, it’s $1.50 at most.

A bunch of bananas (1 kg), 1/2 of a 5-pound bag of all-purpose flour, 1/16 of a box of baking soda, 1/6 of a 48oz bottle of neutral oil, and 1 quart of whole milk will give you at least 3 good loaves that aren’t loaded with sugar- close to a day and a half of caloric needs- and run you up about $4.90 at the grocery store.

I had to know this intuitively from the time I fed myself on $50 a month.