None of these areas have as much objective value as coastal California - the prices shot up later when they were seen as affordable alternatives, and are falling first as the market cools off.
The prices shot up for the same reasons foreclosures are up. The majority of new homes are built in these regions, and nearly every new home built in California is of the "luxury" variety (i.e. 500K and up). Of course no one can actually afford these prices so the builder financed them with so-called no income verification loans.