I'd keep an eye out on Amazon. They take some time, but when Apple updates their products, Amazon will clear their older inventory with some pretty heavy cuts; For instance the 24" white iMac is currerntly about $1600 (2.16, 1gb, 250gb, new) which the apple store has refurbished for $1449.. I'd expect Amazon's price to drop another $200 to $400 in the coming weeks, plus their usual rebate, plus free shipping and no tax for most states.
As a point of reference, when Apple updated their MacBooks, Amazon cleared out a bunch of BlackBooks for around $900; The same BlackBook one week earlier was $1500. So if you don't mind getting slightly older revisions, or just prefer the aesthetics of it, I think Amazon would be a good place to look.
P.S., I bought both my current Macs from Amazon.