Which of the following statements best captures the concept of consumer surplus?
Multiple Choice
I paid $105 for a phone last week and just saw the same one for sale now at $75.
I saw a sale on phones, so I bought two.
I was willing to pay $100 for a new phone, but I bought it for $80.
I was willing to pay $100 for a new phone, but they are selling for $150, so I did not buy.