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wait, does this really happen? there must be a reason?
Rental cars are pretty cheap in Orlando, and parking is generally free everywhere you go. So if you are trying to save money, I would just get a rental car.
What people often forget is that the Disney World is huge. They own an entire zip code, and their "driveways" are miles long. I think it'll get pretty expensive quick to be taking Uber and taxis around.
If you really want to save money, I'd utilize buses, private vans, free shuttles from hotels, etc. They aren't as convenient, but they'll be much cheaper.