What
@TheGuyThatMakesSwords wrote is good advice - if you traditionally go to WDW once every two years, it would make sense to figure out how many points you need to get the sort of accommodations you prefer, and buy half that amount. DVC members are allowed to both bank a year's worth of points AND borrow from next year's points when necessary.
I'd add that if you only go every other year, you might want to look into buying resale as opposed to buying direct from DVC. This is an assumption on my part, but I'm guessing you go elsewhere those alternate years. Buying resale will place some restrictions on the non-Disney places you can use the points...but you're only buying half of the points you need and you'll only need them at WDW (and I believe resale points can at least still be transferred to be used through the RCI timeshare company, but not for the Concierge Collection, Disney Cruises, Adventures By Disney; someone will correct me if I'm wrong.
Now if you still need to figure out how many points you'd need for the resort you'd like to buy into, various websites have points charts but I find this the most convenient...
https://www.dvcrequest.com/cost-calculator.asp
Put in the dates you'd be likely to go (for this year anyway), and click the button that says "Show Point Amount" and it'll give you (wait for it) the point amount for every DVC resort, every room type, every view category. Example:
Those point values might vary a little year by year (if October becomes more popular, the values might go up), but those changes have to be offset elsewhere (example, the point values for another time of year or another type of room will have to go down), to maintain a balance as to how many points the entire DVC resort is "worth;" in other words, legally, they can't just decide "wow, this place is popular let's raise the point values 10% across the board." Because technically your points represent a teeny tiny percentage of the resort you own (until the deed expires and it all goes back to Disney). For them to rise point values across the board is the same as saying "yeah we told you you owned this much but now you own less than that," and that's not legal.
But for now, if you think you'd like to own at Bay Lake Tower with a theme park view in a studio, that would require 218 points, so if you bought 109 points and banked or borrowed, you'd have what you need. You might want to get yourself some flexibility by buying more than the bare minimum you need at this time...125?...in case there's a change in the points structure. Then the question (or ONE of the many questions I'm sure you still have) becomes if you go through DVC and see if they have points for Bay Lake available (or if they have to put you on a waitlist), or if you want to buy resale.
Hope that helps.