In marketing, the idea that people are willing to give up something of value or to experience costs (e.g., time, money, embarrassment, the discomfort of changing habits) in order to receive something they value is referred to as :

Exchange

Explanation: An exchange has occurred in Marketing whenever two or more people trade goods or services in order to satisfy a need or want by offering some money or goods or services in exchange. Every exchange should produce "utility," implying that the value of what is offered for trade is less than the value of what is received from the trade. Therefore, the idea that people are willing to give up something of value or to experience costs such as time, money, embarrassment, the discomfort of changing habits etc. in order to receive something they value is referred to as exchange.

$100

Explanation:

From the information, on a Friday night, you have the choice to either go to a Katy Perry concert or a Lady Gaga concert. You won a free ticket to see Katy Perry but you would pay as much as $180 to see Lady Gaga perform, even thought the tickets to her show cost $100.

This illustrates that the person must be willing to pay at least $100 to see Katy Perry. Since the person wa.willing to pay $180 for Lady Gaga even when the tickets were$100, then you should be able to pay at least $100 to see Perry