Suppose Susan decides to join the Photography Club. Which result would be a cost?

 - Susan will have more fun in the Photography Club than she would have had in the Theater Club.
 - Susan will spend more time in the Photography Club than she would have spent in the Theater Club.
This result is a cost. It involves giving up or spending something that Susan wants or needs:
Susan will spend more time in the Photography Club than she would have spent in the Theater Club.