I purchased an OKW resale contract about 15 years ago. It had points available for the current year plus points from the previous year. I bought at a considerable discount from what a direct contract would have cost. My family and I have used the points about ten times in that span of time and I have rented any excess points to avoid them going away.
No regrets. I has been a good deal for us, primarily because we have gone on average at least every other year. As we are maturing in age (enter retirement), I suspect we will travel to Disneyworld less often and work on the travel bucket list. The DVC will likely become less useful and will rent points out more frequently.
Caution, do not buy a ton of points, figure you will only go once every two years or three. Determine what size accommodation you will likely use and decide on how many points that frequency would require and shop re-sale contracts based on that scenario. Also, buy the resort you would be most happy with if a time comes when that is the only resort you can find availability.
Good luck.