New shoes before the race?

I have been alternating between 2 pairs of Asics 2150s since June and racked up about 300Miles on each pair. I am coming to the end with these shoes and I can feel the classic traits of needing new shoes. The shoes have lost that perfect balance of new shoe but broken in feeling, they are starting to smell from the long hot runs of the summer, and the bottoms are starting wear out in the classic overpronater spots. I expect that I can go another 150Miles on these 2 pairs, but that will put me right in the middle of Nov and the Richmond Marathon. I think I should get a 3rd pair to bring into the rotation before the race. If I am going to do that I better act on it in the next week and get the new pair broken in while I taper.