That's a strange example of opportunity cost, especially in the context of college.<p>Having finite money and having to choose what you spend it on is a very simplistic example of opportunity cost.<p>More applicable to college students and gets at the core of opportunity cost a bit better, I think: "Go to a hackathon/job interview/conference, or go to class?" or, for some students, "go to a party or stay in and study?"
Interesting article, but I had to view source to be able to read it. People who browse with JavaScript turned off see a blank page on your site (at least on Firefox 25).