Yeah.
That's a real nice place.
As with most construction, the "finish out" can really drive up the costs.
I'm currently building a 1200 sq. ft. studio from the ground up. It has a large live room, 2 iso's, and a big control room. It also has a separate Kitchen and bathroom.
I had budgeted about $55,000 for the project. I ran a cost estimate, and including a 15% contingency, come up with about $45,000 for the project.
I'm acting as the general contractor, and sub-ing out everything I can't do myself, i.e. Concrete, electrical, plumbing, roofing and HVAC. My cost estimate was based on hard bids from the subs, and actual material costs.
To date, I'm still on budget! The "big ticket" items left are electrical and HVAC and doors. Yes doors! I had a budget of $6000 for doors, and I just re-checked price and availability of 6 of the door I'm going to use. When I checked prices in December, they were $350 each. Today, they're $550 each.
Well, that's why I had such a high contingency. Of course I'm saving a LOT by acting as the general and doing everything I can by my self.
So that's about $46 per sq.ft on the high end, and around $38 per sq. ft on the low end. I doubt you could do it for less than that. I'm using the high end number because I want the finish out to be real nice.