The 1 million system included the room (house addition). To add a room that has such thick custom concrete walls and all the other acoustical details within, you would easily be in the area of $250K in today's dollars. Only going to get a fraction of that back when the home sells.
I consider my listening room to be "large" at 800 square feet, but 1,600 square feet? Not sure I would want to spend the money to fill such a space up with sound. Ken had a typical audiophile dream, but the size of his dream - and the help he enslaved to meet his demands was not eccentric- but extravagant- if not unreasonable. Strikes me as extremely selfish.
He could have spent a million on a building/room that was commercial in nature and provided a financial return for his family. It would seem that it was always about Ken and his self-centered dream.
I read all the articles and watched the video on YouTube of Ken showing his son around his room. His son seems detached and simply along for the ride.
In the end, I felt Ken was likely compelled by Narcissistic Personality Disorder (NPD), a mental health condition that involves an inflated sense of self-importance and a need for excessive attention and admiration. Those with NPD have difficulty understanding and caring about others' feelings.