> The $100k per year for incarceration includes food, medical care, counseling, maintenance, facilities, etc. The cost just for housing is dramatically lower than $100k/year. You are comparing just the cost of housing with the cost of taking care of all a person's needs.

I wouldn't start by saying that the US prison system takes care of any inmate's needs, even if they spend a fabulously large amount of money seemingly earmarked for that task.

Long term, permanent housing is always going to beat incarceration, when we're talking about the same population. It might cost more at first, but those costs are overwhelmingly fixed and then much smaller future variables. The variables that aren't covered (food, medical care, etc., as you've correctly observed) can often be transferred from carceral programs. Fewer people in prisons also means less money spent on maintaining the physical and human plant; some 20% of the individual costs listed above.

Comparing a fixed property purchase price to a yearly estimated recurring cost isn't a direct comparison

Assuming a $700k unit has an estimated lifespan of 50 years. That's $14k/year, we could say $20k/year with a generous maintenance allowance over the life of the home.

So in this example that's $80k/yr remaining for food, utilities, care, etc.

It's probably not accurate to say that jails are adequately taking care of all a person's needs, and certainly not to match any sort of expectation that they'd have outside of the walls of the jail. Being in jail means you've given up a lots of rights that would be required outside of those walls (such as privacy).