Final answer:
Consumer surplus refers to the difference between what consumers are willing to pay for a product or service and what they actually have to pay.
Step-by-step explanation:
The term 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 what consumers are willing to pay for a product or service and what they actually have to pay. It represents the additional benefit that consumers receive beyond what they had to pay.
For example, if a shopper is willing to pay $100 for a product but only has to pay $80 to purchase it, then the consumer surplus would be $20.