I would never buy more points than you reasonably plan to use consistently. Keep the extra cash if you have it, invest it wisely, use the investment earnings to buy more points whenever you need them (you can always find someone willing to sell you points). Using more
DVC to offset the cost of DVC is - sorry to say it - financially quite foolish.
From the financial standpoint, DVC contracts are a below average asset for investment. You couple not a great return with considerable risk. Not only are you locked into a recurring cost model that you have no control over, but you are subject to the risk that the rules change, that the Disney market goes sour, or that some crazy macro event happens (like, I don't know, a scorched earth cultural war with the DeSantis administration that results in a Budweiser effect or the laws being changed unfavorably), all with the best case scenario of recognizing revenue that is only double your recurring costs. You would be investing $22,000+ to maybe make $1,300 per year with the possibility of getting that $22,000 back in 20+ years -- you could do better with an S&P 500 mutual fund.
Don't get me wrong, I'm a DVC member, but I don't look at it as a financial investment. Happy to have the ability to sell my points, if needed, but I didn't buy them for that.
EDITED TO ACTUALLY APPLY YOUR FACTS: My $22k/$1,300 example above was a hypothetical where you were buying 150pts at $150/point and able to hold the contract for a long period of time. That probably doesn't work for OKW for a number of reasons. In your case, your investment would be about $11,600 and you'd be looking at maybe making $640 per year off the points. At some point OKW (along with the other 2042 expirations) contracts are going to devalue on the resale market, steeply and quickly -- not imminently, but it's going to happen in the next 10-15 years. Your contract is not going to retain equity long enough for you to even break even off the annual rental income. Adding these extra 80 points is going to be virtually guaranteed to be a loss. Again, if your plan is to use them most years, then a financial "loss" is perfectly fine. But, if you're just adding them to get some upfront savings, you're going to lose more than you'll save. Again, just put the $11,600 in a low-cost S&P 500 mutual fund and use the earnings to offset the cost of those occasional add-on years.