Very doubtful you would get even 50% of your money back. My house is currently on the market, I've highlighted the fact that we have a media room, pre-wired for 6.1, and the room layout is optimzed for home theater. None of the prospective buyers seem to give a rats butt about home theater. You have to keep in mind we are a very small niche market. Most folks don't care about high end HT. They think a TV with tiny speakers randomly piled on top of it is a home theater system.
If people are into HT. I imagine that they would want to purchase their own set up, it's a huge long shot (IMHO) that you could find anyone who wants to buy your house, AND wants to pay full price for your HT gear.
