Do just call the various websites, and ask, "What is your best price on XYZ?".
I am in the market for a receiver, and am considering the Denon 2112, 2311, 2312, Onkyo 609, 709, 360, and 370. I check various sites (accessories4less, vanns, jr, crutchfield, frys, etc) daily, and it will ultimately come down to whatever I find first at a great price. My current receiver isn't broken, so I'm in a good position to sit back and wait for a steal.
However, being able to call up these websites and get better prices is a new concept to me. Any insight you can provide would be great.