With the net value of my salary of $ 172.82 I will pay for a music course that costs $ 72.82, I will buy $ 50 in computer games and I will set aside another $ 50 to use on weekends when I go to the movies. I decided to spend my money on these activities because they bring me a greater satisfaction benefit than if I used the money on other activities. However, of course, the opportunity cost (which you give up on money for opting to spend it) exists because I fail to earn a considerable income from my bank application, ie I could make my money yield but I prefer to use it at my leisure.