On a shopping trip, Melanie decided to buy a light blue coat made from woven fabric. A tag on the coat stated that the price was $79.95. When she brought the coat to the store's sales clerk, Melanie was told that the coat was on sale, and she would pay 20 percent less than the price on the tag. After the discount was applied, Melanie paid $63.96, $15.99 less than the original price. Was the value of Melanie's consumer surplus from this purchase $79.95? $63.96? $15.99? Or some other amount? Briefly explain.