For a rule of thumb, I shopped and shopped and finally booked throught the local AAA office and savings for 4 adults, 2 rooms at All Star Sports was roughly equivalent to getting the Dining Plan free for all of us. Also, through AAA there are discounts on things with the Diamond Card, but most of that is food, not important if you buy the DP. However, they also discount tours, and the Keys to the Kingdom tour is awesome!!