BLUF: What is the (VERY ROUGH) cost per sqft to frame and dry in a shed dormer?

Context: I’ve renovated a few houses as a general contractor/carpenter trapped in the life of a military officer.  The house I’m in now needs extensive renovation to make it fully what we want including an 8 foot foundation bump-out and three stories of construction up with a roof removal, etc.  Huge job.  The architect drew up amazing plans but my equally amazing builder just won’t be able to meet my budget given the complexity.    We plan to stay in this area now that’ll no longer HAVE to move anywhere so I initially didn’t mind the costly renovation.  Now a new house on the next street over has popped up and has me seriously thinking.  It’s non-split-level construction and topagraphy make it seem much easier to expand into the space we need for our 5 young kids.  The “second floor” even has a finished stair way up and landing area, and then two full height doors that open to the two unfinished attic spaces.  (see pics)  I’ve calculated and think we can renovate this for a lot less overall, but my wife is dreading moving one more time and starting over with the wallpaper removal and other much needed updates.  She would feel much more comfortable if someone could tell her what it would cost to dry in the dormers. (I’d do the finish work) 

What do you experts think it might cost to frame, side, and generally dry in a minimal height shed dormer about 20 feed long on the middle of the pictured roof line?  This is upstate NY near Alabany.  Assume middle of the road Pella windows and everything once opened is as perfect as can be.  Height from subfloor to bottom of the ridge beam is 10′ on the high side and 7’4″ on the short side.  Thanks!