Before you get too excited, $500 probably no longer buys a house in Detroit, gentrification making headway even in a city that is a shell of its former self, and $500 buys you not so much a house, but a shell, gutted of all its valuable parts and in need of massive amounts of rehab work. The author of A $500 House in Detroit: Rebuilding an Abandoned Home and an American City tells his amazing adventure trying (and eventually succeeding) in rebuilding a beautiful house, which among other feats required him to spend a winter there with no heat (and a Halloween night with a gun, ready to defend the house against violent pranksters in a city where police may take an hour to arrive).
The story includes the interactions with his neighbors, who initially view this young white man with suspicion but turn out to be incredibly helpful. It also includes commentary about the reasons for urban blight, which is the least successful part of the book. (And I could not help but notice that he is not exactly helping the city coffers by not pulling any permits for his building work.) But the overall adventure is well told and full of hope for a rebirth of Detroit and other similar cities.