With Audi about to offer a $78,900 A6, and Mercedes-Benz offering something similar in the E-class, you'd have to think a GS 250 would be a certainty now, no? Either that, or the price of the GS 300/350 would have to drop by $20K (and get the fuel consumption reasonably close to that of the the competitors' entry-level models).
add the options on it at it no longer becomes that price