I would answer with a question,what is the value of ANY vacation? I personally spend my 'extra' money on trips,experiences, things that aren't necessarily what other people choose to spend on... Disney and otherwise- for us it's either experiencing something new and different,or experiencing something 'traditional' that we have all loved for many years (read: WDW) I place a lot of value on trips big and small- and spend my money accordingly,vs. in other ways.
This will sound odd, but compared to a lot of other options, Disney is a relatively "cheap" vacation. That makes it an attractive option. Where else are you going to get a full day of high-quality entertainment for $60ish/day? We saw a show in Vegas last week and the tickets were twice that for a 90 minute performance.
It's also fairly "easy" as vacations go. Sure, you can research until your eyes go crossed, but really it's pretty easy to put yourself in Disney's hands from the moment you get off the plane. There's not much worry about "what are we going to do today?" at WDW.
Cheap & easy are a big part of the value for me!
I have a tendency to compare a WDW vacation to other vacations if you are asking about their value. If you are discussing value in a monetary way WDW vacations can be less expensive than other vacations due to discounts that can be found, staying offsite, no dining plan, etc.
As far as a "personal" type of value, I have had other vacations that I enjoy and are glad that I have taken, but aren't quite as much fun as WDW. I am lucky enough not to have to choose one vacation over the other, I can take more than one a year. If I did choose from one trip a year I would visit WDW every other year and see some of the rest of America on the other vacations.
Yup. I pretty much price out a different vacation every year, and Disney almost always comes out cheaper. Sure, there are vacations that can cost less, but their inclusions are less substantial. For example, I could go and spend a week on the beach, but if I want to do anything other than sit on the beach while I'm there, I'll pay a premium for it.
One of the things I've been looking into lately is Mackinac Island in Michigan. Once I throw everything we'd want to do while we were there, it's easily as expensive as Disney, especially if we stay in one of the nicer hotels and much less convenient.
I'm going to an all-inclusive resort in Cancun with my Mom for her 50th birthday this summer, and for 4 adults the cost is right around $4000. Most of that is prepaid with a very restrictive cancellation policy. I could have probably planned Disney for less than that, but she wanted the beach. I spent hours sifting through various different deals, and I'm still not even sure that we got the best one, but I can't change it now.
Then there's the fact that I have a 2 year old right now. He hasn't been to Disney since he was 3 months old, and he's going to flip when we get there. It will be so convenient. If we went pretty much anywhere else, we might have to deal with driving ourselves to unfamiliar places for significant distances. At Disney, we can hop on the bus and play as a family until we get to the parks.
Our last vacation was a house rental on a beach in the Philippines. Since we lived in South Korea at the time, it was a very inexpensive vacation (less than $2000 for a week). However, getting there was an adventure. We wanted to be kind of off the beaten path. So we ended up with a 4 hour off-road drive out into the middle of nowhere with a 1 year old. We could have done a more popular area, but we would not have gotten the experience we wanted, and it would have been more expensive.
The value for me is how much I get for my money and the convenience. I can plan a Disney vacation in my sleep (my Disney dreams have already started for my next trip). Everything else requires a lot of research to find what I want, and even then I can't be sure of what I'm getting until I get there.