I was wondering if anyone out there knew the going rate for a used NHT SW2P subwoofer combo (SW2 speaker and MA-1 amplifier) . . . . I know that one sold last week on Audiogon for $150, but that seems a little on the low side to me for an average. I'm looking to buy one, and I want to make sure I make a fair offer whenever I find one . . . . Any info appreciated!