There is so much about your personal and use info that we don't know that likely would affect our answer. In general IF you'd go at least every other year and stay in those same deluxe type of units,
DVC would save you money only either for a studio or 2 BR compared to two studios. A 1 BR likely wouldn't but would give you more value. This assumes deluxe at a modest discount and reasonable increases in both DVC fees and deluxe room rates. This also assumes you'd pay cash for DVC and don't have other financial issues.
Compared to fee dining vs getting the DP with DVC, DVC will likely not save you money. It is unlikely that the FD will cont in such a way you can use it most trips but it's possible. One thing you might consider is buying less DVC points and doing both at times. That way you can take advantage of FD when available and still benefit from DVC. Otherwise you should likely not buy right now, you can always buy resale later, almost certainly at a cheaper relative price, if the FD runs out.