Detroit prices were so low that the only way they could go was up ! ( in some areas )
Not everyone will relocate just to buy cheaper - the lifestyle, weather, family ties etc, enter into it.
Florida has good weather (except for storm threat), the beach etc. And for a while, prices were so low here that they had natural room for expansion. However, they are now reaching the tipping point of being too high for regular working people
As for the high end of the market - in addition to the appeal of the area, Florid and Texas are the only two states that allow unlimited bankrupcty protection for a homestead (as long as not a criminal charge pending) - so folks from out of state build or buy expensive properties for that reason, after they saty in it a one time stint long enough to declare it a "permanent residence" , it can stay empty and use it for holidays /a few weeks a year.
RE is echoing the rest of America - a growing divide of wealth and shrinking opportunities for working folks and professionals both to earn a decent income or buy property which was a traditional anchor of stability and equity..