This is an interesting post from Slate (bastion of white privilege). It uses data from Zillow. It is a good story the only problem is some cities like DC, Boston, SF are very small so because of the Modifiable Areal Unit Problem (MAUP) the comparisons are not fair. They should be based on housing 10 miles from down town (CBD) as price per squar foot will be higher near the CBDs. So NY has lower SQ price than DC but Manhattan is twice as expensive as SF which is tops on the list. Detroit is a mess no matter how you look at it $12 a square foot vs. 660 for SF.