Suppose Ronald decides to eat the apples. Which result would be a cost?

 - Ronald will get to eat the apples. The apples will be healthier than the banana pudding would have been.
 - Ronald will give up the chance to eat the banana pudding. Ronald thinks banana pudding would have tasted better than apples will.
This result is a cost. It involves giving up or spending something that Ronald wants or needs:
Ronald will give up the chance to eat the banana pudding. Ronald thinks banana pudding would have tasted better than apples will.