d300s price stable but d7000 already cheaper than d300s?

What gives? which one is actually a better camera(technically?) I read that d7000 is way head in term of D.R, what gives to the price of d300s which in digital age is an obsolete camera but priced about U.S 200 more. and the price of D90 too doesn't go down but actually closing in to a second hand D7000.