I am really wanting to upgrade my subwoofer. Currently I'm using the sub from...please, nobody laugh...an Aiwa bookshelf system :b So, I've been looking for an Acoustic Research ARS500 for the past year. I cannot find them for a decent price. They normally go for $500, but the lowest I can find them is on the yahoo shopping sites for around $700. Anyone know where I can get one of these for the normal $500?