8 to 10 weeks prior to arrival is the 'magic' time period for airline airfares. If the airfare seems high check it again around 8 weeks out. ( I usually start pricing out about 10 weeks, checking it several times a week )
I know on our last trip at around 10 weeks prior it was 460.00 from Chicago. A week later it dropped to 298.00.
Unless your schedule is set and you have to be on a certain flight then I'd wait to book until much closer.