Suppose Scarlett decides to make vegetable soup. Which result would be a cost?
Scarlett will save some time. The onion soup would have taken longer to make than the vegetable soup. Scarlett will give up the chance to eat the onion soup, which would have been tastier than the vegetable soup.
Scarlett is deciding whether to make onion soup or vegetable soup for dinner. She wants dinner to be as tasty as possible. But she is also hungry and wants to eat soon.
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 Scarlett wants or needs:
Scarlett will give up the chance to eat the onion soup, which would have been tastier than the vegetable soup.