Check
www.allears.net under the "beyond the parks" section. They list all the activities and prices. If you have AAA or a Disney Visa, there are discounts available for the tours. Usually they are 15% off.
When you see everything you can do, you'll see that it's almost impossible to take full advantage AND get on rides in the various parks, particularly during busy times. If you go in the summer when the parks are open very late, you're a bit better off, but you'll be in constant motion. In addition, we found that knowing the property very well and where things are located in relation to one another makes scheduling a whole lot easier.
I remember telling someone they were going to spend all their time in-transit when she posted her schedule AND meals.
As someone noted above, you are heavily scheduled when on one of these packages. I use a calendar software package to keep track of where I have to be and when. On some days, we have 2 tours scheduled. On others, just the spa and parasailing - of course, along with meals.
We find that a big time saver is to have room service breakfast every morning.
Oh, if you're big foodies, WDW is not the place to go. While the signature restaurants are higher quality, they are not real high end restaurants. V&A is the exception, and is not included in the premium plan. However, the signature restaurants are far better than the regular ones.
Remember, you're paying for atmosphere
Over the years we have found that 1 week in WDW can easily cost as much as 10 days in Hawaii - with the Hawaii hotels being far nicer.