"Teaching about the price of movie snacks is one of my favorite political economy lectures. I begin by asking how many students think movie popcorn is 'too expensive?' About two-thirds of students raise their hands (with the other third sleeping). I then ask, 'How many of you continue to purchase it?' About half of the hands remain raised. 'Well, then, for those of you who continue to purchase it, it isn’t too expensive.'"
And Prof. Gill dispels other false ideas about your favorite movie theater: they have a monopoly on what you eat in the movie theater and they only make money on concessions and not the tickets.
Link here for the full article and a great lesson on how items do get their price.