The fact that the The New iPad™ has a 9.7" retina display at the same price point as the iPad 2 tells us that prices have come down for that display size. But I still think it'd be mighty pricey for 13" to 17" displays.
Apple doesn't usually shy away from mighty pricey though. I'm surprised they don't offer it as a high-end option for an Air at least. Just call it Rarefied Air, and tack another $400 on to the price.