Disney has no 'real' competition when it comes to Disney World or Disneyland, but it likes to be nice to help its image and lower prices for tickets. It knows that once you get inside the park, you will get hungry, thirsty and want a souvenir, so you will be willing to pay anything for those items instead of leaving the park for decent priced food and drink. Basically, Disney makes up for the discounted ticket by gouging on prices inside the park.