NewEgg currently has two GeForce 6800 GT retail boards selling for less than $400, which are indeed great deals considering just a month ago you would be lucky to get one for less than $450 which is well above the list price.
Those cards I mentioned are from eVGA and Albatron, $392 and $399, respectively.
If you would like to pay a bit more you also have offerings from xFx (I currently own one of these babies) with and without the full version of Doom 3 bundled ($413 and $405).
Finally if you are more of an ATI guy, currently the cheapest X800 Pros I found were InfoTek's and Sapphire's, selling for $422 and $425, respectively. Definitely not a bad time to upgrade your videocard.