Dan,
I've had decent luck on eBay for amps....not sure I'd ever buy stuff with moving parts (ie CD player or Speakers) there unless they were NIB.
Not much to go wrong on an amp, especially if you are buying THE GOOD STUFF....used is a good way to save some serious $$$. I routinely picked up my personal favorite a/d/s PQ20's for around $200-$250, when they sold new for around $800 ea. That frees up money for lot of other goodies I needed also............. /forums/images/graemlins/thumb.gif