The secret to a discounted AP:
Buy a ticket from an authorized ticket reseller that a) has the largest discount from its own price, but b) the tickets gate price must be below the price of an AP. Use the ticket once to enter a park, and then upgrade to an AP.
Last fall I bought an 8-day Non-Expiring Hopper from a reseller for about a $45 discount from the gate price for that ticket. Used it, and then paid $4 and change to upgrade it to an AP (because in comparing gate prices, that ticket was the "closest without going over" the price of the AP, while still giving me a decent discount.)
If you're not a Florida Resident or DVC Member, this is really your only way of getting a discount AP.
-Rob