The prices were supposed to have dropped as wholesalers started to get their hands on them, but from what I've seen they've only gone up. With super-apps like Half-Life 2 and Halo on the horizon, they seem to be bringing up price to meet demand because people aren't thinking about Christmas shopping yet. ATI will soon be cranking out more Radeons (like the highly-clocked 9800 XT which is just too cool for non-hyphenated adjectives!), and that will trigger a price drop.
In observing prices on Pricewatch.com, I've seen it go from $270 to $290 for OEM cards. This represents an unusally high market price point, and it's bound to slow sales. People don't generally buy $300 video cards for others as Christmas presents too often, so the principal buyers of the cards--the primary users purchasing for themselves--will most likely be tightening up their belts and buying less personal-use items. Low sales will cause products' prices to drop, so you can expect the lowest prices in mid-to-late October, but that hinges upon then the release date of the new Radeon 9800 XT (presumably the same day as HL2).