I'd have to agree that you're unlikely to recoup additional investment at the point of resale.

Kitchens and Bathrooms sell houses. It's probably 50/50 that the space you adore as a home theatre will end up as "the kids playroom" or "the office".

I think the one exception might be if you have a very large luxury home (like 4000+ sf) where all of those other needs are already satisfied.

Just barely $0.02.

bibere usque ad hilaritatem