Greg wants to buy a used car and he would like to avoid buying a lemon.

He knows that for him, the value of a good car—his marginal benefit—is

$20,000. But Greg has a low income, some spare time, and he knows how to fix a car, so he would be willing to buy a lemon if he could get it for an appropriately low price—a price equal to his marginal benefit from a lemon, which he says is $10,000.