Dues are calculated on a per point basis. Somebody with 400 points at a given
DVC resort pays twice as much in annual dues as someone with 200 points at that resort.
The rate is based on actual operating expenses, property taxes, reserve funds for major maintenance, and a contractually set management profit. The rate varies between DVC resorts, reflecting differences in expenses. The rate will go up over time as costs increase with inflation or because of added services (such as the addition of a 24-hour tended security gate at the entrance to OKW). Although DVC dues are higher than typical timeshare dues, DVC has done a good job limiting increases.
I remember being slightly concerned when I first read a DVC budget. Many of the operating expenses went to other Disney entities. For example, the cable company was Vista Cable and the telephone company was Vista Telephone -- both owned by Disney. Even the local government -- the Reedy Creek Improvement District -- was (and still is) completely controlled by Disney. This raised the question of whether Disney could profit by inflating the charges that DVC members pay.
As DVC members, we have to take it on good faith that Disney will allocate expenses fairly. For example, the costs of the Luna Park pool and operating the BWV lobby and front desk are undoubtedly allocated between the BWV (DVC) and the BWI (not DVC). Is the split based on the number of guests, or the number of rooms, or square footage, or the number of check-ins, or some complex formula? I really don't know, but I assume DVC uses a basis that's fair and legal.