You can check on Trulia or search for towns such as Bayhead, Beach Haven, Point Pleasant Beach, Margate, etc., for just the home values. The infrastructure in some of these areas looked war-torn. The police station in Bayhead, completely gone. The fire department in another town, completely gone. Not to mention the coastline itself. The fishing industry, marinas, etc.
Say what you want about Christie, say what you want about NJ, but the fact remains that the destruction of this area from this storm was/is a nightmare. I can't imagine what the cost will be to rebuild coastline to protect the inland from future storms will be.
Using your formula, sadly, I imagine the cost to be even higher than currently estimated.
http://www.nj.com/news/index.ssf/2012/11/hurricane_sandys_destruction_a.html An analysis of aerial imagery by the Federal Emergency Management Agency shows more than 500 buildings were destroyed outright, reduced to piles of debris, caved in or sliced into chunks.
An additional 5,000 structures suffered major damage from flooding or high winds, and some 24,000 were seen with minor damage. Floodwaters settled in tens of thousands of others, according to the federal agencys preliminary damage assessments.