There is a lovely mirror leaning against the wall in my garage in England. My wife thinks we should sell it. I think we should give it away, to which my wife tut-tuts. She argues it is a beautiful mirror and believes it will fetch a handsome sum on the Internet. I disagree. So, the mirror sits there, ignored for the time being, and not selling, and I hold the Endowment Effect fully responsible. 

The Endowment Effect explains how we value our possessions more highly than others do because they are ours. It is one of the reasons some prices for products and services end up too high. It is also the subject of this episode of the Intuitive Customer.