Costco, AAA, travel agent for best DCL deal?

[jayally]

I just booked a 4 day sea, 3 day land package with Disney cruise line. This is our 2nd trip. The first one I booked with a sponsered travel agent and got a small rebate but was told by others to book through DCL first and then transfer the reservations for the discounts. Does anyone have any advice to who has the best deal? Should I leave it where it is? I have AAA and costco. We are extending our stay to take advantage of the remaining 4 days on the park hoppers by using a priceline hotel. I will be renting a car and we want to add on Disney quest and water park options. I booked for November 2007. Thank you!