Opportunity cost

Opportunity cost is the value of the best alternative you gave up in order to do what you chose instead.

Thinking in opportunity cost means judging a choice by:

1. Identifying the single best alternative use of the same time, money, or attention.

2. Comparing the option in front of you against that alternative, not against nothing.

3. Accepting it only if it beats what you are forfeiting.

The real cost of anything is what you can no longer do because of it.