Audio systems can be very expensive, as we all know. Mine cost more than my 4x4 pickup truck and my Lexus combined. But, I also have a Frieghtliner tractor and trailor and it costs less then that.
Doesn't bother me to think about it at all. For what I get from listening to music, the fun of playing around with the system, and the audio friends I have met, I have no regrets about the cost.