Final answer:
Consumer surplus is the term used by economists 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 is the difference between the price a consumer is willing to pay for a product and the actual price the consumer pays for it. When a shopper gets a good deal on a product, they are able to purchase it at a price lower than what they were willing to pay, resulting in consumer surplus.