I apologize for commenting, to the extent that I haven't been to the party and therefore can't testify from personal experience, but for what it's worth, I think so much of this depends on one's subjective idea of "a lot of money." At 2015 pricing, MVMCP would cost $79/adult and $74/child, or $311 for my family of four (with one child over age 10, and one under). Obviously, we'd expect that cost to increase in 2016.
Alternatively stated in terms of my own finances and budget (both Disney and otherwise), attending the party for a few hours would cost the same as:
(1) a third of our monthly mortgage payment;
(2) an additional roundtrip flight to Orlando from upstate NY or a week's worth of Disney dining for one adult;
(3) 1 more night in our WDW moderate hotel AND 2 more days' worth of multi-day tickets added on for the whole family;
(4) a month's worth of groceries;
(5) dinner at any Disney signature restaurant for the four of us, in most cases with money to spare; or
(6) gas, hotel and museum admissions for a weekend at just about any tourist destination within driving distance of our home;
(7) an extra 8 months' worth of support for a Tanzanian child (education, health care, supplemental food, clean water) who we sponsor through Compassion International (sheesh -- thinking about her really puts the amount we spend on WDW -- or any other kind of non-essential expense -- in perspective).
I investigated the party extensively (our next planned visit is in November 2016) and we came to the conclusion that although the idea of "having the MK to ourselves" sounded amazing, that experience is not guaranteed (and is getting rarer, as WDW increases the number of party guests each year), and we already get a taste of that experience with rope drop arrivals and EMH. A few more walk-ons, a pretty parade and gallons of hot chocolate just aren't worth the expenditure for us, when we could use the same money to do things that we would value more. Again, "worth it" is going to mean something different to everyone, and I realize that I live in an area of the country where money goes further than it does in some other regions, so what is chump change to some seems like a lot more to me.