Walt Disney World has two offers for UK guests which can be used in conjunction with each other.
The first gives a free Disney Dining plan to every member of a party when booking a 5 night (or more) stay at Disney Moderate Resorts, Disney Deluxe Resorts or selected Disney Deluxe Villa Resorts. The second gives guests a 14-day Ultimate Ticket for the same price as a 7-day Premium Ticket.
The free dining plan includes one quick-service meal (such as a McDonalds), one snack (such as a cake or a bottle of coke) and one table-service meal for every night of the visit. Given the cost of food at Disney World, this can be a huge saving - £20 or more per person per day.
The saving on tickets is less significant, with 14-day Ultimate Tickets actually only priced marginally higher (in the region of £10) than 7-day Premium Tickets on most websites.