Theres no reason for the price to move significantly if at all unless AMD releases a card to compete directly against it. How the R9 380 stacks up against the GTX 970 is more important. A 1.2GHz Tonga XT might have a chance against a GTX 970 but will need to be priced right.
r9 390X won't move the needle for anything except maybe the GTX 980, and make Nvidia release a competing Ti card.