Actually the prices quoted by Marionnette were only valid for certain nights. you can get a discount on ticket for certain nights by buying in advance, being and annual passholder or a DVC member. Here is the cost/dicount breakdown from 2011 (from allearsnet)
Prices for the party are as follows (all prices listed include tax):
Advance Purchase for September dates: $57.46 for adults 10 and older / $51.07 for ages 3-9
Advance Purchase for October 2, 6, 10, 11, 16, 18, 20, 23, 25, 27 and November 1: $60.66 adults / $55.33 ages 3-9 (No Discount Available for October 28 and 31)
Passholder and DVC Member Discounts for September dates: $53.20 / $46.81
Passholder and DVC Member Discounts for October 2, 6, 10, 11, 16, 18, 20, 23, and 25: $56.40 / $51.07
Day of Event (if still available) for September dates: $63.85 /$57.46
Day of Event (if still available) for October 2, 3, 6, 10, 11, 16, 18, 20, 23, 25, 27 and November 1: $67.05 / $61.72
Day of Event (if still available) for October 28 and 31: $72.37 / $67.05