Several shirts on one rack alone looked good; no one was head and shoulders above the others, though. Once I had about four shirts in mind, each consequent shirt was subject to much more scrutiny. I looked at the price tag of one and saw that it was $22, twice as much as the others and only marginally nicer. Instead of being put-off that the shirt was more expensive and thus not an option, I was relieved to have narrowed my decision.
This seems to conflicts with one of the general assumptions of economics that people are rational. In theory, my reaction to the higher price was entirely irrational. Why should a consumer wish to see a higher price on a desirable good under any circumstance? How can mental "tricks" overpower rationality in seeking contentment.
However, it can be argued that my actions were, in fact, rational. If I can assign a price-value to NOT having to make a decision about 5 shirts but rather just 4 shirts, then I can weigh opportunity benefit against opportunity cost. Let's suppose that the marginal opportunity benefit of the $22 shirt vs. the $11 shirts is actually just $2 (that is, I value the more expensive shirt by only $2 more than the cheaper ones). Let's also suppose that the marginal opportunity cost of making a more difficult decision is $3 (it pains me $3 worth to have a tougher decision). From these suppositions we find that marginal cost exceeds marginal benefit by $1. Therefore, my response to the more expensive shirt was entirely rational.