If you want to pay the full gate price, yes but when you enter. Online is still significantly less expensive. The ticket booth is to the right of the main gate, well marked
Meijer also sells tickets
Tickets can be prepurchased at meijer and some other locations. It's about the same online though. Full price at gate. Plus there's generally a longer line. I recommend buying parking online too. It'll save you five bucks.
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