I was under the impression (given to me by the CM who sold me my AP over the phone) that when I was ready to upgrade to a premium AP, the premium pass would be pro-rated based on the amount of time left on my AP. Any knowledge of this? We bought APs in December, and did not want to add the water parks at the time. I was assured that when I added the water parks in the spring, I would not have to pay full premium upgrade price.