Although VB is less expensive in the short term, the MF's are much higher and any savings you get now, will be eaten up in just a few years.
Since you are planning to go to WDW, I would consider SSR. MF's are lower and the price per point is not that much less than VB.
However, if you are someone who will only be booking a few months in advance, IMO, you may be disappointed with a
DVC timeshare. Availabilty on that little notice is hit or miss. Depending on the type of room you want, you may or may not have luck securing a reservation for the entire stay.
And, DVC off season times are not the same as the parks. For example, early December is a slower time for the parks but extremely busy for DVC.
Most DVC members book during that 7 - 11 month window and from what I understand and have read here on the boards, last minute reservations, while not impossible, are becoming harder and harder to get as the number of members grow.
Just something to think about as I would personally hate to see someone buy in to DVC thinking getting a room is easy on short notice, only to find it hard to use the membership.
Good luck!