Just beware that SXSW (huge Austin event) is going on March 7-16 2014. Airfares during that time are likely to be much higher than normal. As long as your dates are outside that event I think you are seeing an average fare. If they are inside that or on either end I would lean toward booking sooner than later. Just my opinion.

I would pay (using cc of course) rather than using miles on this route. There is a lot of competition. Southwest, Frontier, Delta, American, United, Jet Blue, probably missing a few all offer NY area to AUS. You are likely to find a deal on one of them. Use miles for expensive routes with little competition.