I never recommend booking anything that you can't afford unless a discount comes out, because there are no guarantees that one will. Even if one does come out, there are no guarantees that your resort will be included, or that there will be availability left by the time you get through to modify your reservation. Room discounts are released if occupancy is too low, so having a room booked already actually reduces the chances of discounts being issued.
Personally, I book what I can afford now or I don't book until the discount comes out. If I book what I can afford now and discounts are released, it's much easier to just book the new discounted room and cancel the non-discounted room later because you have the option of booking the new room online instead of having to wait on the phone. I would say most of the time I wait to book until the discounts actually come out, but I understand that many people have to coordinate airfare and other things far ahead of when the discounts are typically released.
So in your case, I might book a room for five at POR now because I could afford it regardless of whether any discounts come out. Then if a discount comes out, I would book the AoA room with the discount first to be sure it's secured, and then go back and cancel the POR room. Yes, there is a chance you wouldn't get a room at AoA because they are booked. But if you can't afford to stay there without a discount, you're going to have to downgrade to a more affordable room if the discount AoA rooms are gone anyway.
