It's a fairly old amp. Seems a bit overpriced to me for its age or was it recently refurbished or something?
As to power draw wouldn't worry too much, I have far more than that on one outlet (four power amps and an avr plus tv for major power uses on that outlet) but I have modest spl requirements. Not sure how you're planning on multich system with an old stereo receiver like the Yamaha, altho it has pre-outs for using an external amp easily enough. Are you trying to run dual stereo sets of speakers or something?