You absolutely can get houses for 300-400K in Detroit. Where exactly were you looking at? Houses that you're describing are definitely possible in hot areas like Downtown and Downtown adjacent areas like Corktown, Indian Woods, and Midtown.
Agreed that you can find $300k houses (and cheaper). I was just surprised that the nicer areas were still pricy. I mean Indian Village, and the neighborhoods you mentioned, have some nice homes, but those neighborhoods feel like an oasis surrounded by areas that are dealing with very tough economic situations.
Again, I was just surprised at the price for places I liked. If I wanted to take a chance on a neighborhood that might turn around in the next few years I could find some deals (although a lot of those homes need a lot of work).