It's hard to calculate when you have a shop rolled in with the dirt work/slab and metal building build out cost. We are finishing up building a barndo in CS with 1900 sq ft of living space, 3400 sq ft of shop, 900 sq ft of porches and 500 sq ft of concrete parking. We finished out the shop as well as the living space ourselves (electrical, plumbing, painting, trim work, window treatments, metal stairs, fixtures, cabinets). We contracted the living space framing, spray foam, sheetrock/texture, HVAC, septic and concrete sealing.
Best I've been able to calculate, we'll end up right around $75/sq ft for the living space and $35 sq. ft for the shop part. I'd say we did go "higher end" on a lot of the finishings just because we were doing it ourselves and saving the money on labor.