If you weren't already, check out GET Travel's pricing for park tickets. They were the best around when we looked, and you have until October 28th I think to choose between having them mailed to you or picked up the day of the expo -- we're doing mail since we arrive on Wednesday before the expo opens.
Also, depending on what airport you're flying into,
SNA at least is allowing Uber to do pickups for a fair amount less than taxis. Lots of airports don't allow them, so we were happy to see that it would be an option for us beyond the taxi and shuttle services.
Just some food for thought while you (and anyone else reading) shop your tickets and transportation.