I've "run the numbers" on the site before, and the flights they give me are always limited in number and overpriced. I'd suggest finding your own flight arrangements, keeping in mind the way your local airlines price their flights. (For example, when I fly JetBlue I book as soon as the schedule is released, because the prices start at their lowest and only go up from there. If I'm flying a bigger, major airline, then often the best price is offered a month or so before the flight. Everybody does it differently...) Once you've booked your flights, you can call WDW and give them your flight information for purposes of Disney's Magical Express transportation from the airport to onsite resorts, if you are using that service.
Sometimes you do save money by booking a room+ticket "package" with Disney, especially if there is a discount offer going on. If your daughter graduates in December and you can wait until January to travel, you will be going to WDW at one of the least crowded, and least expensive, times of year -- a low price "season" during which WDW has typically offered room discounts and/or free dining. That doesn't mean that you should delay your booking to wait and see, however. WDW discounts aren't limited to "new reservations," so you can go ahead and book the trip now, and if a discount comes out later, you can call WDW and have it applied to your reservation.
