I must admit we never bother with the planning and stress of this. We've been going once/twice a year in recent times and just book a deal with BA, get a car with them as it's usually cheaper than direct with other places. Then every other time we skip Disney World and just do a load of driving to different places.
It's gone up cos the $ is stronger, and prices have naturally increased anyway, but still can't beat it. Just a happy place to be if you don't get chewed cos of the queues for rides etc.
The parking is a piss take, but as you only pay once no matter which park you goto, we just hop around them. Do a bit in each, then go somewhere else for the evening if needed, then maybe pop back for fireworks.
Love the place and will keep going back.