Suppose Cameron decides to plant the amaryllises. Which result would be a cost?
Cameron will give up the chance to look at the magnolia tree. He thinks it would have looked more beautiful than the amaryllises. He will save some space. The amaryllises will use up less space than the magnolia tree would have used up.
Cameron is deciding whether to plant amaryllises or a magnolia tree in his backyard. He wants to make his backyard more beautiful. But he also wants to leave space for doing fun things.
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 Cameron wants or needs:
Cameron will give up the chance to look at the magnolia tree. He thinks it would have looked more beautiful than the amaryllises.