I agree with Minerva. You should rent points for a DVC Grand villa or a couple of two-bedrooms from someone here on the boards. You'll save some money by renting from a member rather than booking one through Disney. The least expensive DVC resort that has grand villas is Old Key West, so that would be your best bet to keep costs down. Also, the main pool at Old Key West has a new water slide inside a giant sandcastle. It looks like fun!

The other DVC resorts with grand villas are Boardwalk Villas and Saratoga Springs Resort.
Points can rent for anywhere between $9 - $12 per point depending on when you want to go, the demand, etc, but usually they rent for $10 per point.
By renting points from a DVC member (at $10 per point) a grand villa at Old Key West for a week (7 nights) would cost anywhere from $3,560 - $5,010, depending on the time of year you go. If you want to go during Christmas/Newyears week, it would cost quite a bit more. Almost all rooms here have a pleasant view of water and/or golf course, and it's quiet, so if you need to get away from the hustle and bustle of the parks for a little peace and quiet while you sit on an extra LARGE patio, enjoying a nice glass of wine, this is the place to be.
At the Boardwalk Villas (at $10 per point), a weekly stay (7 nights) in a grand villa would cost between $5580 - $8000. Christmas week would be more. Of course here, you'd be close to the boardwalk with lots of restaurants, bars, and entertainment. It's walking distance to Epcot and MGM. You'd most likely have a nice view of the boardwalk area and the Illuminations fireworks, or a nice pool view, if staying in a grand villa Also, this is where you have the fun clown slide.
At Saratoga Springs Resort, a weekly stay in a grand villa would cost between $5050 - $7190. Christmas week would be more. You could have a great view of Downtown Disney, it has a terrific spa, they're starting to offer horse-drawn carriage rides soon, and it's withing walking distance to Downtown Disney for great restaurants, bars, and entertainment.
The other DVC resorts, Wilderness Lodge Villas and Beach Club Villas, could easily accomodate your party as well, but you'd need to rent either a couple of two bedrooms, or a two bedroom and a one bedroom. Both of these resorts are also spectacular, as are all the DVC resorts. Wilderness Lodge has a quieter ambiance for relaxing, with it's spectacular lobby and themeing. Beach Club Villas has lovely beach decor throughout, and of course the most spectacular pool you ever see at any resort anywhere.
Hope this helps you, and have a great trip!
