I bought a 2021 Indiana State Park Pass. It cost $50. In my pedantic thinking, I will need to visit an Indiana state part at least 8 times in 2021 to recover the $50 cost. Assuming, of course, the average entrance fee is $7 for In-State Residents. Out of State people are given a $2 penalty.
If I gather enough energy and motivation and exceed the required 8 visit quota, then the average cost of each visit declines. So, I am therefore motivated to exceed the required 8 visit quota.
At one time in my recent life, I vowed to hike every marked trail in every Indiana state park. I bought an Indiana State Park Pass at that time. In my excitement, I drove two hours south to Spring Mill State Park. Due to my perpetual out-of-shape condition I could not hike every marked trail in that park. I realized I would need to visit the same park several times to hike every trail. And, in my pedantic thinking, expenses, costs, time requirements increased exponentially and I gave up on that quest.
Maybe I will pick up that quest again. Maybe this time I will understand that fulfilling such an epic quest might not be achieved in a single year under the purchase of a single Indiana State Park pass.
If you are interested, this page lists all the entrance fees for Indiana Department of Natural Resources properties.