Offhand thought. Building costs in urban area's are stuck in a high cost 'peak'. Everything is expensive which makes construction expensive.
My experience renting some warehouse space in SF. One building three units. Used to be occupied by three roofing companies. And some meth heads living in the old offices. One of the roofing companies bought it, kicked out one of the other roofing companies and the methheads and rented to us.
Change of ownership and new owner kicked out another roofing company. And rented out to a pot grow. Fast forward 5 years we got kicked out along with the remaining roofers and all three units are now growing pot.
So went from three roofing companies circa 1998 to three pot grows circa 2012. My feeling is stuff like this is happening in every urban area in the US. Which means your roofer is either paying very high rents or commuting in from 2-3 hours away.
Really easy for me to see that driving costs up by 100%. That's born out by what my insurance agent says. Rebuilding costs in SF are $600-1000 sqft. Get out to Vallejo drops to $300-500 sqft.
Other thought as well is that typically you get better margin on luxury goods than basic ones. because it's easier to slip more profit into high cost goods, like granite countertops vs laminate. Prices double, your margin doubles but your expenses only go up 50%. So as long as the luxo market isn't tapped out that will be serviced at the expense of basic goods.