Suppose Amanda decides to go on the pirate ship. Which result would be a cost?

 - Amanda will give up the chance to go on the Ferris wheel. She would have had more fun on that ride.
 - Amanda will save some ride tickets. She needs fewer tickets to go on the pirate ship than on the Ferris wheel.
This result is a cost. It involves giving up or spending something that Amanda wants or needs:
Amanda will give up the chance to go on the Ferris wheel. She would have had more fun on that ride.