Basically you want to buy the ticket with the greatest savings off gate price from Disney BUT costs less than the AP you want to buy. Then, once you've used the ticket to get into a park (thereby bringing its value up to the gate price) you can upgrade it to an AP by paying the difference from the gate price of the ticket and the AP. For example (using phony numbers) if the
UT ticket costs $200 and the gate price of that same ticket cost was $230 and the AP costs $450 then your equation would look like this:
$450-$230 = $220 -- This is what it should cost you to upgrade to an AP, again this is a phony number.