I don't know where your flying from, but the dates you're flying are not prime time travel to WDW.
You shouldn't have too much trouble checking for discount fares on one of the travel sites like, kayak, expedia and Orbitz.
I wish I had a special formular for you but unfortunately it's a day to day thing checking for fares that you're happy with both schedule and price.
Check this DIS thread to see what I mean, http://www.disboards.com/showthread.php?t=2259533
When you find a fare your that your happy with both the schedule and price, you found your sweet spot.
We found our sweet spot back in May '09 for our April '10 School vacation/Spring break trip.
Good luck all,
Joe
Our Authorized Disney Vacation Planners are here to provide personalized, expert advice, answer every question, and uncover the best discounts.
Let Dreams Unlimited Travel take care of all the details, so you can sit back, relax, and enjoy a stress-free vacation.