We are finalizing plans for our June trip and I'm just wondering how it works to upgrade park hoppers to APs. We're starting with park hoppers to get a MM and use the park on a Sat (our last day which is an AP blockout date). So we want the hopper perks and then will upgrade just before we leave. Here's my main question. I am planning on buying three of our tix through Home Depot where we get a good corporate discount which is less than the Disney.com price. I'm going to purchase one ticket from the Disney website and get the new Visa membership discount. This tactic saves us $74. But when I upgrade to AP, will they look at the amount I actually paid to determine the difference, basically making all the discount-hunting a moot point or do they just use a basic face value for all hoppers regardless of where you bought them and what you paid? Just wondering how they determine the price difference between your park hopper and the AP? Can anyone fill me in?