Sorry, forgot to mention. I think that the 150wpc rating is accurate IMO. I've had mine running hard during some demos and it's clean and LOUD (too loud for any sustained time).
I'm using an MM9000 in my system. It replaced the internal amps of my Yamaha 2092 receiver. I immediately noticed more dynamic range and clarity when upgrading. I would say that the price they are quoting you is fair, and the amp is definately worth an audition.