I've been watching the price of my go-to subwoofer on Amazon lately and it seems to be stuck at $129. I broadened my google search a little and found this on Ebay:
ebay.com link: Polk Audio PSW10 BLACK 10 Monitor Powered Subwoofer NEW
I suspect this is a scam since it is obviously too good to be true. I've had good luck with getting refunded for purchases that never shipped in the past, so I took my best shot at it... will report results.