Not that I like reservations, but you could always just change the reservation real quick to whatever park you'd prefer to start at. It's really not that hard (though it is annoying).
The value of the passes comes from when you use them and how. If I take one trip starting December 1st for 10 days, it'll cost me $855.35 (through Undercover Tourist). If I take two five day trips, one starting November 1st and the other December 1st, the cost is $699.10 + $746.60 = $1445.70. Same amount of days, very different prices. So I don't believe
@monothingie is correct in placing the value of the pass at 20+ days. If you went nonstop, sure, but that's not how most are using the Incredipass. If my wife and I did three weekend trips of three days, we'd save money buying the Incredipass.
All that to say, what this really shows is the obscene prices of daily tickets.