Suppose Tommy decides to plant the gardenias. Which result would be a cost?
Tommy will give up the chance to look at the palm tree. He thinks it would have looked more beautiful than the gardenias. He will save some space. The gardenias will use up less space than the palm tree would have used up.
Tommy is deciding whether to plant gardenias or a palm 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 Tommy wants or needs:
Tommy will give up the chance to look at the palm tree. He thinks it would have looked more beautiful than the gardenias.