Question for High-End Rehabbers/Flippers

[Mark Graffagnino]

I'm looking at a deal that would be a pretty high-end rehab and flip in Atlanta. ARV will be about $700K. In order to get to that ARV I'd need to add a master suite over an existing garage that is 400 SF. I've done this exact type of project before, but it was on my personal house and it was 8 years ago.

My question is- for preliminary budgeting purposes only, what is a good $ per SF number to add a master suite?  Not including the additional structural issues I'll need to include for the existing garage, but just to add the space including the floor trusses.  I want to say I spent about $150/sf back in '08.

Thanks for any input.