Good point about state and sometimes local tax. Here in GA, it's 7%. 7% of a new Audya or (gasp) Wersi

, is a lot of moolah. Imagine if we could buy our new cars over the net and bypass taxes. New car dealers would instantly turn into warranty and service facilities. We can blame everyone else, but in the end, it's our willingness to forgo both amenities (like after-sales support, knowledgeable sales staff, etc.) and ethical considerations (like demo'ing and not buying), in pursuit of the best prices. You get what you pay for.
chas