Suppose Pam decides to bake bran muffins. Which result would be a cost?

 - Pam will get to eat more muffins. She can make more bran muffins than apple muffins.
 - Pam will give up the chance to eat apple muffins. She thinks apple muffins are tastier than bran muffins.
This result is a cost. It involves giving up or spending something that Pam wants or needs:
Pam will give up the chance to eat apple muffins. She thinks apple muffins are tastier than bran muffins.