The biggest residential job I was involved with so far, the customer spent over 2 million with the Audio/Video subcontractor alone. This included streaming audio and movies to 32 rooms with sat radios, tuners, mp3 servers, sat tv and cable boxes, video projectors and plasmas, many high end audio systems in special rooms, the kaleidescape , hvac control, lighting control, pool and spa control, security system control, pan/tilt camera controls, ipod docks with touch screen remote, the complete phone system, and all the touch panels and programming for it.
My company sub-contracted to the hardware guys to do just the control programming, which came in at around $100k after all the changes and adds were done, and took about 6 months of total programming time spread over about 2 years. This job actually caused the hardware dealer to go bankrupt due to mismanagement of the 50% down payment.

So if you ever hit the lottery and want to go with a larger setup, feel free to get back to me.