That's about the size room I asked Francis Manzella about at FM Design. I'll call in next week for more details.
He pointed out The possible costs involved in a high quality surround capable mastering suite can run from $125/SF up to $400/SF. On the small scale you are talking (approx 500 SF room plus support spaces, totaling less than 1000 SF).
And furthure added Fees for a single room mid-high level mastering suite design would run in the area of $15,000 - $18,000 for interiors fit out only. This would include everything from floor, wall and ceiling construction through acoustic finishes, electrical installation and mechanical specification along with all detailing. It does not include design or consulting required for any structure which would be additional.
Brad, is this inline in comparison to your devloping situation?
Ed