> Fries and a hamburger are about the easiest thing to make, requiring no special equipment.

For all practical purposes of modern urban life, you at least need some kind of specialized heating apparatus.

More importantly, somewhere to store that apparatus. Which is quite often a kitchen. In San Francisco, the median housing cost per square foot is almost $1,000. A small kitchen is defined as 70 square feet, or $70,000. If we assume a rate of 3%, the opportunity cost of that kitchen is almost $6 per day, or $2 per meal if we assume three meals per day.

That brings the cost of an $8 McDonalds meal down to about $6 right there.

Then there is your time. San Francisco has officially declared that your time is worth at least $13/hr. At that rate you have just 28 minutes before you've already used up that $6. That includes gathering the ingredients, prepping the food, cooking the food, and cleaning up afterwards. That does not leave a lot of room for error, even for something as simple as burgers and fries.

It does indeed get better with scale, but I have also left off a number of other costs, including the cost of the food itself. For a single person (in SF) it is no contest without even getting into other costs.

Of course, there is something to be said about the food you can create yourself, versus eating at Mcdonalds every meal. Cost isn't everything.

There's also the fact that you can't just buy enough to make one hamburger and some fries. At a minimum, you can buy enough to make 2-3 hamburgers (and you'll have leftover buns, cheese, etc). So now you have to store that extra stuff (more sq footage and refrigeration costs). You might not eat it all (and it goes bad, meaning you throw it away). Or you might freeze it for later (maybe - some things you can't freeze of course).

I don't think you can get an apartment without a kitchen.

Of course, that doesn't mean they are free. There is a very real cost to having the means of production.