Just to give you an idea, the most basic Crestron system (which is referred to as the SmarTouch system) retails for $3600.00. That includeds an RF wireless touchscreen (the model ST-1700C) and a control system with (2) one way RS-232 ports and 4 IR ports (but you can Y the IR ports to get more IR outputs).

It does not have two way feedback on the touchscreen, which can be very useful in some circumstances. Otherwise, when I say basic, I don't mean to indicate it is lacking. It will do everything most people need for theater control.