Off property you still have pay for transportation, food (if you don't do the dining plans), etc. That brings the price back up. The theming, the amenities, the convenience of staying on property, is where the value is. And yes, value is subjective.
We stay off property because my family bought into a Marriott Time Share really early on (before DVC was around). We love it, but we also know of the added costs that go along with it. Rental car (s), groceries, 20 minutes back and for to the parks....driving when exhausted.....
Again, I have paid $139 a night for a hotel in Des Moines. In May. And that was the cheapest around. I saw no value in that. Especially since I've paid $99 a night for the same room at different times of the year. It's also about demand.
You're paying for food, either way, somewhere. The dining plan might (and I stress might...it's hit and miss depending) be a discount on the food you (the global "you") consume, but you're still paying for it. Now....off site doesn't have access to "FREE Dining promotions"..but those occur during a very limited set of dates, with other restrictions (rack rate and, now, ticket differences) that will likewise effect value. As an off site guest, though, you have considerably more dining options than MOST on site guests (who don't have their own transportation), at considerably lower prices, too. Being generous, I'd say food costs is a wash.
Transportation (rental car), parking, etc...those are all increased costs vs on property.
By the by, a midsize sedan will run you between $130 to $200 a week (depending on discounts and how/where you book) plus gas. If you have a particularly good corporate contract with a particular rental agency, or find a particularly good coupon, you can sometimes get that down to around $100 a week. Parking is about $85 - $119 (depending on 5 or 7 days in the park). For your 6 nights of lodging, that bumps your cost about $50 a night.
When you're talking about a $200 - $300 a night price difference in room rates (I'm talking Deluxe)....it's easier to bear that $50 a night.
The convenience factor is certainly to be considered, as is the theming, when determining subjective value. Nobody can do that part of the value calculation but you...so if we're coming down to that...fair enough. Surely, though, it's obvious why some might not value that as much as, say, you and I, would.
Amenities? Not so much. You can get better amenities, in the strict hotel definition, for MUCH less off property. Disney doesn't do resort amenities all that well, class to class, compared to other hoteliers. Again, compare the GF to the 4 Seasons. There isn't, really, any comparison.
I think the Moderates and Values def hold up better in a value calculation than the Deluxe hotels do.
