Spoken like someone who's never had to struggle with money. I applaud your success, either inherited or earned, but not everyone is able to have such a devil-may-care attitude about their finances.
While I don't think
MNSSHP is expensive in terms of value in comparison to the rest of WDW's pricing structure, it is a pretty extravagant cost for a birthday present, particularly when you'll have to buy at least two tickets, if not more. Obviously this isn't the case for everyone, as some people can afford such extravagance, but for many people this would be living well outside their means.
I've seen more than a few people say, "If this is what she really wants, it shouldn't matter how much it costs." This logic baffles me. In a perfect world everyone would like to grant their children their every wish, but this doesn't work in reality for two reasons: 1.) The aforementioned money issue and 2.) Just because a child wants something, doesn't mean they're entitled to it, even for their birthday. That's a lesson more people could probably stand to learn. There are more than a few 16-year-olds who
really wanted a car for their birthday, but alas, they'll still be riding the bus.
To the original question my best advice is to save up for another year, perhaps someday you can grant your daughter's wish. Until then, I'm sure you'll find no problem making each of her birthday's special, with or without Disney.