Final answer:
An economist would use the term consumer surplus to describe what happens when a shopper gets a "good deal" on a product.
Step-by-step explanation:
The term that an economist would use to describe what happens when a shopper gets a "good deal" on a product is consumer surplus. Consumer surplus refers to the difference between the price a consumer is willing to pay for a product and the actual price they pay. When a shopper gets a good deal, they are able to purchase the product at a price lower than what they were willing to pay, resulting in consumer surplus.
For example, let's say a shopper is willing to pay $50 for a pair of shoes, but they find them on sale for $30. The consumer surplus in this case would be $20 ($50 - $30), representing the value the shopper gained by getting a good deal.
Economists study consumer surplus to understand consumer behavior, pricing strategies, and market efficiency.