Have you checked out the disney uk website yet? They have OKW and Saratoga Springs villas at a huge discount for next year (think it's about 40%). You could get a two bedroom villa at either resort for much less than a room at the GF.
We've booked 5 nights for August 2010 with free Quick Service Dining Plan - even though we have upgraded to the Disney Dining Plan, when you take the cost of the plan into account, our studio at OKW is effectively costing us £35/night for the room. However, note that you have to buy tickets and room as a package with Disney to get the free dining.
It may be worth pricing up a package with a couple of the tour operators (Virgin Hols, TCD, Thomas Cook, Cosmos etc) to get an idea of package prices, then when flights are released (usually 330 days before date of travel) have a look at flight costs plus cost of booking accommodation separately.
Just had a quick check on the Disney website, and for 14 nights accommodation per room (no flights!!):
GF - approx £3,600 including free Disney Dining Plan
Wilderness Lodge - £2,200 including free Disney Dining Plan
Port Orleans/OKW - £1,400 including free Quick Service Dining Plan