Suppose Andrew decides to eat the sunflower seeds. Which result would be a cost?
Andrew will get to eat the sunflower seeds. The sunflower seeds will be healthier than the peach cobbler would have been. Andrew will give up the chance to eat the peach cobbler. Andrew thinks peach cobbler would have tasted better than sunflower seeds will.
Andrew is deciding whether to eat sunflower seeds or peach cobbler for an afternoon snack. He would like to eat something tasty, but he is also trying to be healthier.
Before you decide to do something, it is often helpful to list costs and benefits.
Costs are what you give up or spend when you decide to do something. Costs involve giving up things that you want or need.
Benefits are what you gain or save when you decide to do something. Benefits involve gaining something that you want or need.
This result is a cost. It involves giving up or spending something that Andrew wants or needs:
Andrew will give up the chance to eat the peach cobbler. Andrew thinks peach cobbler would have tasted better than sunflower seeds will.