Also, the purchaser is sometimes on the hook for the back taxes (in his case $6K). I'm not sure how MI law works, but if the purchaser is on the hook then he's actually selling a lot with a condemned house for $6,500. Which is not an amazing deal, since vacant land in nicer rust belt cities goes for $10K-$30K and demolition is expensive. Again, not sure, but if that's how it works in MI then it makes sense that he's having trouble selling a lot with a condemned building and $6K in back taxes at pretty much any price. You're going to burn mid five figures before you have lien-free empty land, which can be had at that price with much less hassle.

In some cities, a condition of sale for city-owned property is that the buyer rehabs or rebuilds within a given timeframe.

> Giving an acre to a homeless person and relocating them there though would be a death sentence.

That's probably a massive over-statement -- even in the most dangerous communities in the US a homeless man probably isn't going to be killed for no reason. And this is Detroit, not the Alaskan wilderness, so there are shelters and so on. But it is true that the land would be totally worthless to a homeless person.