HOWEVER, if you buy
DVC and use it exactly the same way you previously vacationed at Disney, you probably will save money.
100% correct. And a lot of people say this is what they do.
Some of them might even be right.
But all of those comparisons assume you would be taking exactly the same number of trips, at the same frequency, and for the same duration. And I suppose there are a few people for whom that's actually true. But I've talked to a lot of people who own timeshares---at Disney and elsewhere---and just about all of them have had at least one of those "well, we may as well go (or book the larger unit, or or or) before the weeks/points expire" trips. Next time you are around the hot tub, see how many long-term DVC owners (10+ years) tell you their vacation habits haven't changed at all once they became owners.
There won't be very many. That's because for most people, owning an expiring asset that can only be used for vacations changes the way they think about vacations---and probably in ways they didn't expect, can't articulate, and don't consciously appreciate.*
Many of those people would travel less (and/or less luxuriously) if they didn't own, and those trips would end up costing less. Are there exceptions to this? Are there people who genuinely are only taking exactly the same trips they would have, and end up spending less? Assuredly! But, by definition, most people are not exceptions.
[There's also the matter of what things actually cost, and my accountant would tell you most people get this wrong for timeshares because they don't account for the up-front cost properly, but that's a different problem.]
This is sort of like how the Dining Plan worked. Yes, if I would have ordered the most expensive thing and the full allotment of courses at every single meal, I'd "save" money. And again, there might have been a few people for whom that was true. But, when left to my own devices, I just don't eat that way--and not because I am trying to pinch pennies, but just because I don't want to.
It is also worth noting that
none of these things are bad. Taking more and/or nicer vacations is great, even if you spend a little more than you would have in the alternate universe in which you never owned timeshare, because timeshare bounds the costs. Heck, most people in the US absolutely should be taking more and better vacations, because we are giving ourselves short shrift. I once had to tell a staff member at my organization that one of their performance goals for the next year was to stop letting vacation days expire. The stretch goal was to reduce the backlog.
But, usually when someone is working really hard to justify a purchase like this by "saving money," it's really because they are trying to talk themselves in to a purchase that, for one reason or another, they think they shouldn't make/don't deserve/what-have-you. Perhaps my biggest point in all this is: You don't have to do that. If you have the discretionary resources for it, and you want it, just buy it and enjoy it and don't worry about the "savings."
Money is for spending, and "discretionary" means "you can do what you want with it".
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*: I admit that I'm a bit of a radical on this point. But, the last 20-30 years worth of "decision science" (which sits at the intersection of psychology, economics, and philosophy) has given some pretty good evidence that (a) no one is ever purely rational, (b) emotions play a much larger role in decision making than we think and (c) it's hard (if not impossible) to consciously be aware of how that happens.
