[mikorym]

You are making the argument that he makes more money than necessary just for food.

It could be that you have—in theory at least—two options:

1) Try to plant corn. 2) Kill a rhino.

There is no option here that makes exactly $3 or whatever is may be that your food need is for that timestamp.

I think he means "people got to eat" as in you need some kind of income.