You buy an Xbox Series X for $499. You would have been willing to purchase the Xbox Series X even if it had been listed at a price of $600. You walk away
feeling like a winner by having the most advanced gaming platform in existence
and Microsoft the producer of the Xbox feels like a winner after making a
profit.
This exchange would be classified as a

a-voluntary exchange
b-barter exchange
c-win-lose exchange
d-involuntary exchange