Determine the amount of producer surplus generated in each of the following situations.
a. Gordon lists his old Lionel electric trains on eBay. He sets a minimum acceptable price, known as his reserve price, of $75. After five days of bidding, the final high bid is exactly $75. He accepts the bid.
b. So-Hee advertises her car for sale in the used-car section of the student newspaper for $2,000, but she is willing to sell the car for any price higher than $1,500. The best offer she gets is $1,200, which she declines.
c. Sanjay likes his job so much that he would be willing to do it for free. However, his annual salary is $80,000.