That's good, because in all likelihood you'll end up giving Disney a lot more of your money buying into their timeshare. That's only a bad thing if your objective is to save money over what you're spending today on Disney. Even in your situation though, the plan to buy and use a small 50 point contract is going to hit a few hitches.
1- You'll end up paying a lot more for a small contract on the resale market. Looking at the the largest resale site, a 50pt SSR contract is asking between $129/point and $144/point. Larger contracts (>50pts) are mostly asking between $107/point and $124/point.
2- The challenge you're going to face is that President's day week is in the highest cost period for Disney's timeshare stays outside of Christmas week and Easter week. 50 points won't get you very far even if you have mad skillz and go full Disney Timeshare Ninja, walking an Animal Kingdom Villa Value Studio year-round every year like a machine.
3- Traveling with a teacher, you'll be tied to higher cost travel periods. Disney's
point charts, do not accurately reflecting high Disney timeshare demand periods anymore. When Disney first created the five-season
point chart, point requirements mirrored cash hotel demand (i.e., high travel periods required more points while low travel periods, required fewer points). Timeshare usage has evolved to be almost the inverse of this. For you, this will be a double edged sword. This is good because higher point requirements normally equates to less demand, so you may have more options on where to stay (see 4 below for caveat). This is bad because the whenever you travel prices will be high with all the usual suspects, Thanksgiving, Christmas, President's Day, Easter, but as an added bonus, as soon as MA schools let out, point costs jump for the summer, and only go down a week before school starts back up again - while your husband will be prepping his classroom for the start of the school year.
4- If you have inflexible dates as to when you will go every year (specific weeks you'll have to travel based on school holidays) you'll need to buy where you want to stay. Being "able" to book at BCV with your SSR points will mean nothing if you're trying to get into a studio at 7-months. You'll have to buy at BCV, and as mentioned in point 1 above, BCV ran for about $165-$175/point for 50 point contracts vs. $145-$150/point for larger contracts.
All that suggests you'll probably need closer to 100 points if you want to continue your pattern of one week year one, two days year two, rinse and repeat. Which ultimately means you likely won't be saving anything over what you're paying today for your moderate room.
There's something to be said about financial freedom. On your current Disney plan, you can turn off the Disney spigot whenever you want. Whatever life throws at you, you can pivot and postpone that Disney trip, be it a pandemic or a home improvement.
The timeshare commitment means that until you sell, you're on the hook to pay the dues regardless of what is happening in your life. And the $15K upfront is just the tip of the iceberg. Nestled snugly beneath it is a lot of annual dues that will need to be paid regardless of whether or not you go to Disney; anywhere from roughly $700-$1,000/year depending on where you buy. On the Disney timeshare plan, over those 10 years you travel, you'll spend between $22,000 and $25,000 for just the room (in today's dollars, not calculated for inflation or dues increases which have historically exceeded inflation).
The longer you use the contract, the less your cost per stay is going to be, but you will likely be spending more than what you're paying now. If you and your husband are cool with that, you'll love your Disney timeshare ownership.