yep.
Advance purchase tickets are $42.55 per adult, 10 and up (tax included) and $34.30 per child, ages 3 - 9 (tax included) for all November dates and for December 4, 5, 7, 11, 12, and 14.
For December 1, 8, 15, 18, 19, 21 and 22, and day-of-event tickets (if the date was not sold out in advance) the prices are $48.94 per adult, 10 and up (tax included), $40.12 per child, ages 3 - 9 (tax included).
the only other reason I can think of is that the closer to Christmas you go, the greater chance they may sell out.
It is sooo worth the price. We go every year.