Well, it's because you have a lot of guests and 2 rooms that the jump from moderate to AKL is so much more. Plus, 7 nights is a pretty long time.
I just got back from the AKL, and I was really impressed. It's a deluxe resort, for sure. I stay less nights and many less people, so it would never cost me $1000 more, but for me, it was well worth the extra $400 I paid approx over moderate, for 4 nights. We spent quite a bit of time resting in the room too, and the entire lodge is such a nice and comfortable place to be.
However, if it's important to keep the budget down, saving $1000 is a huge amount of money. For me though, I've now realized that the resort is a big part of my stay, as much as the parks I think, and I really loved the AKL.