Suppose Maria decides to bake lemon muffins. Which result would be a cost?

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