No need to get so envious as if it's unattainable!
Surely it is a great setup, but many of the effects can be had at far more reasonable costs.
For example, projectors can be replaced by a decently sized widescreen LCD Monitor, just put it behind the wheel and it can be quite huge. It can also be put level to the horizon, so the horizon in game and real life are the same height in front of you, which enhances immersion. Many people with projectors sit below them and look upwards. The closer LCD screen also lets you disable wheel rendering and have the monitor become a window into the game world, like a professional sim cockpit.
Also, with a larger widescreen LCD, you only need that one screen. No need for three.
A surround sound stereo system may sound nice, but you'll be left hearing everything else - CPU fan, box fan, graphics card fan, power supply fan, plasticy gearchange sounds, steering wheel interacting with desk with FF effect sounds, your own desk chair squeek sounds etc. And the surround sound speakers don't sound perfect - sound will bounce off the interior walls/floors/ceiling/objects and get tainted by that no matter what. A set of sealed good headphones can sound superior, and greatly enhance immersion by blocking out all the unwanted environmental sounds. The cost to sound ratio of headphones is something like 1/5 of stereo speakers, meaning for the same cost, the headphones sound roughly five times as good.
The G25 is more or less a must have for awesome immersion though!
Anyway, there are many paths to simracing bliss. This is but one of them.