As a member, you can purchase an Annual Pass for $100 off the regular price. There is a limit of 8 per household and all adults must have ids with the same address as the member.
Note that I believe those are prices which includes a $100 discount available to DVC members. The prices for non-members are higher and DVC retains the right to cancel our discount at any time.
You must remember that DVC is a timeshare. That means you are buying "time" at a lodging place which just happens to be in Disney World. It is not a "prepaid vacation", but instead is pre-paid lodging. Meals, transportation, park admissions, etc, etc, etc, are not included. There are certainly "perks" that pertain to those activities (such as the $100 discount on annual passes), but those perks can and do change frequently.
Also, as with all timeshares, there is an annual "maintenance fee" to pay just like when you own a home or anyother real estate interest.