Suppose Kevin decides to eat the peach cobbler. Which result would be a cost?

 - Kevin will give up the chance to eat the chips. The chips would have been healthier than the peach cobbler.
 - Kevin will get to eat the peach cobbler. Kevin thinks peach cobbler will taste better than chips would have.
This result is a cost. It involves giving up or spending something that Kevin wants or needs:
Kevin will give up the chance to eat the chips. The chips would have been healthier than the peach cobbler.