We're going in JULY, so no judgment here on the June trip! We have a timeshare as well, so are in the same boat.
If you have an Entertainment Book (those books kids sell for fundraisers you can also just buy them online) They sell ticket packages at a discount and often have a couple of free days tacked on. Ex. 7 day Water Park and More for the price of 4 Day base ticket.
AAA includes free parking (which can add up for sure, since you're driving in every day) in a priority lot and sometimes has a little discount as well.
I think what we'll do is get ONE of the tickets through AAA (since we're only driving one car), and the others through Entertainment Book.
I'm too afraid to use any of the smaller vendors.