My read of the parent’s comment is that you aren’t paying for land.
You don’t need store bought fertilizer. I had a garden for a few years and avoided manufactured fertilizer for most of it. At an industrial scale, sure, it is needed, but not at an individual garden level.
No transportation needed other than your own two feet or what you can build. It’s not like you need to go into work every day.
You don’t need to buy animals for food if you can hunt and trap.
I’m not suggesting I agree with the $100/month limit, but things on your list are considered luxuries to the plan. Remember, you’re shooting for “QOL of someone that lived in the American West a hundred years ago” which wasn’t all that great.