considering just equipment (and not room build out costs, treatments, etc.), what % of the overal equipment budget do you say needs to be invested in a 5.1 speaker setup? in other words, in a budget for receiver (or preamp/amplifier separates), front speakers, surrounds, center, subwoofer, cd/dvd player, etc. (ie all the electronic hardware), what percent of that total budget should go into just the 5.1 speakers?