There are many Disney Vacation Club break-even calculators floating around the Web. They require assumptions such as rate of inflation, how dues will increase, and what your average vacation accommodation cost is.
A ballpark figure to break even on your DVC contract is 7-10 years. If you want to take a look at your specific contract price and vacation needs, one nice Excel calculator I found is here, hosted by DVC Resale Market.
Here are some screenshots of the calculator:
I like the simple interface on the first tab and the ability to look at the running totals on the second.
DVC Resale Market also runs a blog where they periodically put rankings of the resort from which it is currently most economical to buy a (resale) contract. For example, in Fall 2021 they note the most economical resort to buy is Copper Creek. Their method of evaluation is similar to mine, so I appreciate their insights.
An important point in estimating the long-term value of DVC is that you might due better investing the same amount of money. Conceptualizing the opportunity cost of DVC for those funds is strongly dependent on personal factors, but generalizations might be helpful. You can find detailed discussions on DISboards about the economics of purchasing DVC, along with a spreadsheet calculator to compare possible outcomes.