I know this field very well, having written a book about building dedicated home theaters, and currently producing a DVD series on the same.
You can build a wonderful home theater for about 10K. I've been in amazing theaters that were well over 200K, and I personally enjoyed my own first 'home theater' which I put together for about 4K.
Myself, I am going to start on a new theater this Summer. It will take me about 2 years to finish, as I will be doing all the work myself, and it will not be cheap when it is done. But, for me, it will be worth every penny and every drop of sweat.
The theaters in that link are nice, but most folks give this desiger, Theo Kalomirakis, the nod as the most well-known in the industry. Feel free to go to his site to see some of his work. The stuff is artwork... beautiful...
http://www.tktheaters.com/gallery/ then click the images on the left hand side for the details and more pictures of each theater.