We saved over $150 on beverages at Disney by bringing in our own 20 oz. beverages and pouring them over a free glass of ice, (20 oz. bottles of soda and water cost $3 there.) We saved $200 by eating cereal, fruit, juice, milk and yogurt in our room and avoiding the Polynesian's quick service counter which served the same. Plus, we bought chips/cookies for evening snacks.
Excellent idea. Saved us some time, definitely.
If you are staying at a Disney resort, you must use Garden Grocer for everything you may need delivered to your door. I won't vacation in Orlando without Garden Grocer !