Most "breaking even" calculations involve staying at the DVC resort by purchasing points vs buying a contract.
I was NEVER able make anything "break even" because I didn't limit myself to DVC points. For example I'd look at Contemporary TPV vs BLT TPV. For a non monorail resort I'd look at being able to get a 2,000sqft house off site w/ private vs DVC at at least half the price, if not 1/3rd.
DVC is really just prepurchasing your vacations. You really aren't buying, your contract expires and you have nothing when it's all over so the idea of "ownership" isn't a real thing. Disney has managed to out ponzi scheme the traditional time share in that regard.
With all the money you are wasting or as DVC calls it, investing, you'd be better off buying a small house near WDW and renting it out via VRBO (or similar) and hiring a property manager when you are out of town and staying in that the weeks you are in Orlando. Then you actually own the property at the end and you can sell it or actually leave it to your children.
I get the DVC draw for some, I get that some people just don't understand and I also get that some people don't care.
Since you are concerned about breaking even and want to stay (presumably) exclusively on WDW property, the easiest way for you to figure out if you break even is to:
1- take your purchase price and divide it by the years you'll have on your contract, yes I'm ignoring the fact that you should figure the lost money to interest payments if you aren't paying cash for it and the lost interest if you'd invested that money but I'm trying to keep it easy. That's your base price per year.
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2- add the yearly maintenance fees.
For us and looking at BLT TPV vs a TPV at Contemporary during the first week of December and assuming at least a 20% room discount based on AP, bounce back or seasonal offers, we came out at saving a few hundred dollars a year by staying at Contemporary. We also did a comparison for moderate as well, same deal.
Things to consider, room rates rise every year but typically not as much as the yearly maintenance fee. DVC rooms are generally bigger but if you want bigger, why aren't renting a house 10-15 minutes outside of the gates for 1/2 to 1/3rd the price? No one stays at WDW for the room sizes lol.
At the end of the staying deluxe or moderate all you have are memories, just like the DVC. If you actually owned anything at the end of your contract, DVC would have a draw for us. It doesn't, it's just a lease.
Also, for us, when you stay DVC you can't get free dining. We like to hit the first week of December every other year because it almost always has free dining and that saves us (4 people) a truck load more... also depending on if we have AP's that year and usually we time the free dining package as the week we upgrade base tickets to AP's
As a family that spends about 4 weeks a year at the parks I've worked every number possible. DVC is a losing proposition no matter how I work it.