There is a (long) argument here (http://www.gwern.net/Sunk-cost http://www.gwern.net/Sunk-cost) that people tend to over-use the concept, since it's probably th

There is a (long) argument here (http://www.gwern.net/Sunk-cost http://www.gwern.net/Sunk-cost) that people tend to over-use the concept, since it's probably the most know logical fallacy.