Rebuild costs - Massachusetts

[Dan Marriggi]

Looking to buy a 2800 sq.ft duplex (stacked units) that needs a total rehab; plumbing ,rewire etc. Lightning hit the roof and basically destroyed it. A fire from the Lightning caused significant damage to the top floor. The bottom unit was soaked by water. It will need to be completely gutted to the studs and rebuilt including the roof structure. Will basically need everything. Any thoughts on  determining rehab costs ?

Remember this is Massachusetts , specifically Boston (Roslindale for the locals)