I think people FEEL cheap and ACT cheap when they forget their true worth and value in the world.
This can happen very easily when people get sucked into a materialistic outlook, and forget about their inner dimension and spiritual side.
The human soul is an amazing creation: it's infinite, attached to God, and can literally achieve every good thing in the world.
We forget that (or are never told it...) and then think that we're here for movies, flings and money etc.
That can cause people to ACT and FEEL cheap. But really? It's impossible to cheapen the true innate value of a human being, and the human soul. If more people knew that, the world would be a very different place.