What I often find so interesting is that the projection and sound systems for a high-end home theatre are so much vastly cheaper than what they are describing,

What I often find so interesting is that the projection and sound systems for a high-end home theatre are so much vastly cheaper than what they are describing, and deliver a surprisingly similar experience. You can buy the best 4k laser home theatre projector that Sony offers for around 20k USD. You don't need an optical block, and you can hook it up to an Apple TV or blu ray player and get high bitrate 4k signal. You can build a very respectable quality 9.2.1 surround system for less than 5k USD. The maintenance costs are negligible with this HT stuff. The trick is getting access to cinema releases, which is essentially impossible for a home user. I'm surprised none of the theatre chains have subdivided their spaces into smaller, more intimate rooms which seat around 8 people and use consumer level kit. Obviously you can build a very nice home theatre for less than that (optoma makes great budget projectors).