Andrew paid $30 to buy a potato cannon, a cylinder that shoots potatoes hundreds of feet. He was willing to pay $45. When Andrew's friend Nick learns that Andrew bought a potato cannon, he asks Andrew if he will sell it for $60, and Andrew agrees, since he would have sold it for $45. Nick is thrilled, since he would have paid Andrew up to $80 for the cannon. Andrew is also delighted.

What is Andrew's original consumer surplus?
$15
$20
$30
$50