Back in the 80’s a Disney spokesperson said the company planned to raise prices every year until 10% of the people that drove to the gate, turned around and left. Now that everything is booked in advance and the greenway speeds them and their dollars right to the park, it seems the policy is still up and running.
I went to Disney World the first year it opened, $3.50 for Magic Kingdom. We took some girls there in or around 1978 it was $6.50.