Just thought I'd share this tip: always ask at your hotel/resort front desk if they have any additional discounts to an attraction. We were in The Dells earlier this week, and the day we were heading to Mt. Olympus we asked at our resort if they had any specials. We already had the Opa card and were prepared to use that. The wonderful lady at our resort (Cliffside Resort and Suites) entered our name in a computer and told us to give our name to the person at the Mt. Olympus ticket booth. We weren't sure what to expect, and even if it didn't work, we still had the Opa card.
The ticket booth worker at Mt. Olympus entered our name and then told us the total for our family of four was $64.00. My husband and I looked at each other in total surprise and then quickly paid. According to my calculations, that was a 60% discount off the gate ticket price!
I have no idea what that program/promotion was, but it certainly pays to ask if there are any deals available.