Suppose you recently sold your used car. Assume that no new production was involved in this transaction.
Wealth was created because the buyer's willingness to pay was the value of your willingness to sell.
Suppose you sold the car for $18,000.
If the minimum price, or “bottom line,” you would accept for the car is $17,000 and the most the buyer is willing to pay is $33,000, then the seller surplus is
and the buyer surplus is
. The total surplus created by the transaction is