> If it takes you more than 10 minutes to pull this from fridge, heat a pan and fry, something is wrong.
Something is wrong, then, because I have to go all the way back to my place to put it on a bun and put things on it and eat it. I don't have to make that commute with fast food.
You two aren't arguing about which is cheaper; you're arguing about which externalities you're willing to ignore.
Literally not being at home to eat home made food is obviously a case where other factors dominate.
However, I really don't think that's the general case people are thinking of when trying to argue that it makes some kind of economic sense for people to eat a fast food diet. The average person does go home at some point, especially so for families.
Or more specifically, it's the claim "I can't go to the grocery store and make this meal for less than a fast food meal", that is absurd.
Something is wrong, then, because I have to go all the way back to my place to put it on a bun and put things on it and eat it. I don't have to make that commute with fast food.
You two aren't arguing about which is cheaper; you're arguing about which externalities you're willing to ignore.