Replacement costs vary enormously so get at least three estimates, in writing.
If you are attempting to price an unusual property using the cost method, your best bet is to seek out a qualified appraiser for your area, and work with a Realtor familiar with the type of property.
Best of luck,
Coldwell Banker Trails and Paths
The generic number by the way is $150. That is never accurate but gives you a VERY rough idea at what you would be looking at for replacement cost. Don't forget, attached garages will increase your replacement cost because they are considered part of the home since it is attached.