Hi,
We were at Fort Wilderness twice last year, once in January for about 2 weeks and once in July-August for about 10 days or so.
Yes, it IS expensive, but as others have said, it is about the experience. One thing I WILL SAY to their credit is they will allow up to 10 people to stay on your campsight WITHOUT additional charges. We didn't take advantage of that last year, but back in 2009, we had my brother, wife & daughter stay with us for 5 nights for no additional charge PLUS they received Disney transportation to and from the airport. For them to stay at a Disney hotel back then would've been an extra $1,000 and we wouldn't have been able to spend as much time with them. This way, every morning & evening we had some good, quality time with each other. And no extra cost! A rare bargain in the "House of Mouse". LOL
We found it was usually quicker to drive directly to all of the parks/water parks than use the bus/boat system. (The monorail was experiencing some issues when we were there last summer.) There were times we did use Disney transportation, but if we were trying to keep to a schedule, we'd drive. If you're a Disney resort guest, you can park for free at the parks.
One thing I will recommend is to learn how to use
FastPass+. This will allow you to make reservations for key rides which usually have a line at them. There are limitation, but depending upon when you go, some attractions have wait times of over 2 hours (Avatar in Animal Kingdom to name one, Seven Dwarfs Mine in the Magic Kingdom to name another. These are both new rides.) With the FastPass+ you can reserve a time and it allows you to walk up to a much shorter line often less than 10-15 minutes. If you're staying on Disney property, you can start making your reservations up to 60 days in Advance. If you're not staying on Disney property, you can make them up to 30 days in Advance. If you're going to be there in their busy season, you'll NEED those days in advance for some attractions.
Think carefully about the "Park Hopper" option. It IS expensive. Yes it allows you to jump from one park to the other, BUT that usually means a long day, and if you have little ones, that might not be possible. Oh, by the way, you can buy any ticket package you want at first, and if you want to upgrade or add features (such as Waterparks or Park Hopper) they let you do so for just the added difference.
It's a great campground. An interesting thing is, though it's pretty much in a swamp, we didn't see a single mosquito while we were there! So it was quite pleasant being outdoors any time of day.
Good Luck, and have a great trip!!!
~Rick