While HH and VB look less expensive in the short term (initial buy in costs), their higher MF's eat up that savings pretty quickly, especially compared to SSR.
If your goal is to be at WDW, then I think SSR is the best value out there (providing you are okay with this as your home resort). It runs around $15.00 more per point, but it expires 12 years later (in 2054 vs. 2042 for VB and HH) and has MF's about $2.00 per point less than the other two. Based on that, any upfront savings would be eaten up in about 7 - 8 years.
And, by owning a WDW resort, you know you can book 11 months out and have a place at WDW. At 7 months, you can always try the other resorts, but if there is not the availability that you need, at least you know you are all set.
With VB and HH, you are at the mercy of the 7 month rule and while getting something on property is always possible, there are times where you could find yourself with a missing night or two right in the middle of your vacation.
Now, if you plan to stay at VB or HH, then buying there would make some sense.
Good luck!!