We got the fall promotion package this year, which sold DH on the trip that he thought would be too expensive. We have
AAA, so got an additional discount and perks with that too. We have 3 kids, so we're just over the "perfect family of four" count for many of the great deals and can't stay in just one room at the value resorts. With the fall promotion (not sure if they are still offering this, but it's worth a shot), we're getting 2 adjoining rooms in Pop Century, 7 day base tickets (opted to not get hopper or water parks since this is family's first trip), and the dining plan for under $3,000.

Everyone had told me it would cost over $5,000, so I guess we did well. Of course, we will still have the expense of getting there (our package did not include airfare because the prices were just too high right now for us) and souveniers, but since we've paid the rest in full, I'm not too worried about that stuff. We'll just have to have a budget and stick with it!
I'm not sure how large your family is, but I would also consider staying in an off site townhome/rental house to cut costs as well. They can be very reasonably priced for a week and you can eat some of your meals there or pack some as well. I've heard from many who've done this and loved it. I just wanted to try to stay on site this time for our first family trip there to extend the magic.