Consumer Surplus
The difference between the maximum a consumer is willing to pay and the actual market price they pay.
What is Consumer Surplus?
Consumer surplus is the economic benefit buyers receive when the price they actually pay for a good is less than the maximum they were willing to pay. It represents the aggregate gain to consumers from participating in market transactions. Policies that lower prices — such as subsidies or price controls — can increase consumer surplus, while monopoly pricing and taxes reduce it by creating deadweight loss.
Example
If you value a concert ticket at $150 but purchase it at the posted price of $80, your consumer surplus is $70. Amazon Prime members report consumer surplus in the hundreds of dollars annually, reflecting the gap between perceived value and the annual fee paid.
Source: Investopedia — Consumer Surplus