The housing market is highly interconnected, as people sell homes in expensive areas and thus drive up prices when they compete for homes in less expensive area

The housing market is highly interconnected, as people sell homes in expensive areas and thus drive up prices when they compete for homes in less expensive areas. This creates a ripple effect as those new markets show price gains, and owners in those areas can sell their homes and move to other further-flung areas. So yes, there are regional differences but they impact each other and can broadly be considered a single market.