He's exaggerating a bit. If he spent $85K on his home theater a decade ago, it's unlikely most of the cash went into equipment that's already obsolete. I'm guessing the TV/projector may be a bit dated, but should cost that much to replace anyway.
Determine what's most important to you, first. FYI, really good sound systems (amp & speakers) will last decades. You can upgrade the video portion of the home theater every 6 years or so if the need arises. A very important, but overlooked part of the home theater design is to check the quality of the video and audio processing of your AVR. You can get pretty bad audio lag in cheaper systems.