I originally called because of a PIN number that I had. When I got a rep, I also mentioned that I'd like to check the AP rate. They transferred me to the AP people, and they were able to pull up the dates I wanted.
The gentleman that helped me was able to pull up the rates because I said that I wanted dining added to my package, and those were already out.
This was at the end of April, so....I would call to ask. See what happens. It couldn't hurt. The only thing you'd be wasting would be a phone call.
I think you got the wrong number. AP rates for September aren't even close to being released. Maybe they sent you to the AP people, but I spoke with CR in both April and May and they told me that the AP rates definitely weren't out. Further, I know that you did not get the AP rate from Disney because you're paying rack rate for your room for
free dining, and the AP rate would not be $300 more than rack rate. It would be at least 15% less. This is, of course, assuming you did not add in the dining after the AP rate in order to get your "$300 more than FD" rate. I would also think that the fact he said "there was no availability to add dining" shows that the guy just didn't know what he was saying; there's not a certain number of people who get dining when they have annual passes, anybody can add it because you have to pay for it. Heck, I can add it from the Disney site! Whether or not you can do that with the room discount, I don't know. But Disney will happily take your money for dining since typically they are making money on people on dining plans.
Also, in as many times as I've been on the phone with Disney reservations, they've never had to transfer me to get me an AP rate or to check my PIN codes.
OP, AP discounts will come out in June - that should be before your 45-day mark. Make the decision then. Every time I've looked at FD instead of my AP, it's worked out to being less if I used my AP. This is after totaling up my receipts when the trip was over, since I always used the AP discount.
You know your family, so if they will eat every meal and every snack, it could be a good idea. But if you're the type to have a quick breakfast in the room, a granola bar for a snack, and only one big-sized meal, the DP could be a money-waster. If you miss even one meal, you lose money.