You can set up a CQC based theater control scenario for as little as $2200. It just requires a small, dedicated controller machine, a multi-port serial card, and for the lowest cost solution a standard 7" touch screen mounted on or between the chair arms (on a swivel if you want to let either side access it), or for somewhat more you can get a wireless tablet (something like one of the new UMPC devices would be a nice choice.) If you need IR, an R2DI 4 zone IR card would be added.
I was running pretty much exactly this type of system for a good while. It was a HushPC box (very small, fanless), with a 4 port serial card, Z-Wave lighting controller, and a standard 15" touch screen on the table beside the couch. It worked flawlessly for a couple years until I replaced it (didn't need to replace it, I just updated to one of our new boxes.) It ran a stripped down XP installation, with just the stuff needed for a dedicated automation system. It stayed up for over a year at a time, and was only brought down a couple times to physically move it.
I'm currently controlling a Sony 777ES changer, Dwin HD-700 projector, HD-Leeza scaler, Lexicon MC-1 processor, Sony HD300 DirecTV set top box, Z-Wave USB controller controlling the apartment lighting. I can browse my movies and music, get weather data, fully control all my equipment with full two way control.
Here are some of my current user interfaces (drawn by me using the interface designer that is part of the product, so there is nothing 'built in' about these interfaces.)
So you definitely don't need to spend $15K to get an excellent theater control system. This is not to say that Crestron is bad, since it's obviously not. It's a high quality product and it has a proven track record. But there are lower cost alternatives for this type of fairly straightforward home theater system, which aren't terribly challenging for the automation system.
The whole cost of my previous system would be something like:
$950 - HushPC system with XP, 40GB drive, 512MB
$650 - 15" touch screen
$90 - 4 port serial card
$315 - CQC license (if you need the full system, as little as $200 for a basic system.)
$50 - Cables, USB for touch screen, and RGB for the video
$150 - Z-Wave, about $150 for the controller and a couple lighting modules.
* If the noise isn't an issue, i.e. the computer is in a closet/rack, then you can get a far cheaper enclosure with fans, and knock another $250 off the price probably.
This assumes of course that you DIY it, and it's not a lot to do, and you could get some professional help for the cabling part if you aren't comfy with that, basically just making/pulling the serial cables and video/USB cables to where they need to get to. The rest anyone fairly computer literate can do themselves, though they may want to pay for some nice interfaces if they don't feel comfortable creating interfaces as pretty as they would like. We have lawyers and manager types as customers who have set up quite nice solutions of their own of this type.
Here is a picture of my old system:
It actualy looks quite nice, kind of gothic. The interface there is from my old interface set, which I updated to the ones above a while back.