You're estimating an opportunity cost here, not measuring it. Goodwill can be measured in the sense that goodwill = purchase price - book value. No assumptions

You're estimating an opportunity cost here, not measuring it. Goodwill can be measured in the sense that goodwill = purchase price - book value. No assumptions are involved in its calculations--goodwill is calculated based on two fixed values. Opportunity costs are not as concrete. In your example above you state your opportunity cost is $2000...but what if that rush project comes through? What if your steady contract scales back for that week? There are assumptions involved; ideally your opportunity cost would be the expected value of all probable incomes during that week. Identifying those probabilities a priori is impossible. My point is: opportunity costs are based on assumptions. They cannot be measured--only estimated.