Suppose Chad decides to bake lemon muffins. Which result would be a cost?
Chad will give up the chance to eat cornbread muffins. He thinks cornbread muffins are tastier than lemon muffins. Chad will get to eat more muffins. He can make more lemon muffins than cornbread muffins.
Chad is deciding whether to bake cornbread muffins or lemon muffins. He wants the muffins to be tasty. But he also wants to make a lot of muffins.
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 Chad wants or needs:
Chad will give up the chance to eat cornbread muffins. He thinks cornbread muffins are tastier than lemon muffins.