azdisneylover, I feel that it needs to be mentioned that you are *never* going to get a deal on an AP. The cost is the cost is the cost.
If you have tickets with a discount, the discount is lost, b/c you're always paying the cost. And the cost of APs is the same for 3 to infinity.
So when we upgraded, we had 2 adult 5 day hoppers and 1 child's 5 day hopper. They were through Costco Travel, and the tickets had the value of the 5 day advance purchase hoppers.
When we bought our APs it was before 2 ticket/ap price increases (wow how did THAT work?), and they were 239. So we paid the difference between the value of the adult hoppers and the AP, so 239 - 189 for me and hubby each. DS's hoppers were a bit under 189, and we paid 239-whatever his was, which means we paid more for his AP at that moment, but ultimately, we paid 239 each in total.
So since each of you will have the kids price hoppers, you will pay the different between the current AP (I assume you're getting Deluxe?) price and the value of each of those tickets. The discount you currently have makes no difference once you upgrade; you're going to be paying the total of the AP prices at the end.
I don't know if you noticed, but DangerMouse is in AZ too, and she visits relatively often. Heck, I live in WA and I visit often (this year) too!
Once you don't have to pay for tickets for a year, it becomes quite a bit easier, if you run across a great hotel deal or a great plane ticket, or you get a chunk of money to put towards gas for a road trip.
So if you even *think* you will visit even once, check out the price different.
When we had our hoppers, we knew we would be back for one more one-day visit. The 189 of the hopper plus the price of a one day ticket was MORE than the AP cost. That did it for us! So if you will be there 3 days on this trip, then might do another 3 day within the 365 day period of your first day at the parks, it will almost absolutely be worth it to put the outlay of cash for the APs, even if you only look at the cost of admission.
Add in the discounts and you're practically making money.

(you have to steadfastly ignore cost of hotel meals and transportation when looking at it that way!)