Opportunity Cost
What is the real price of a decision you can afford?
The idea
Choosing one use of capital means giving up another.
In the real world
Inventory funds cannot simultaneously finance marketing.
Going deeper
Affordability asks only whether the money exists. Opportunity cost asks what else it could have done, which is the question that determines whether a decision was good.
The reason it gets skipped is that the alternative is invisible. Money spent on stock shows up as stock; the marketing, the hire or the debt repayment it displaced never appears anywhere, so nothing prompts you to weigh them. Making it explicit means writing down the two or three best competing uses at the moment of deciding, because afterwards there is no record that they were ever options.
Where it stops applying
Applied to every small decision this is paralysing. It earns its cost on choices that are large, lock up resources for a long time, or are hard to reverse.
Why it matters
It stops affordability from being the test, because the money is only free if nothing better was competing for it.
Try this today
Name the best alternative to your current investment.
Test yourself
A company has £50,000 and can afford to increase inventory. It does, and stalls anyway. What was not on the balance sheet?
Show the answer
The marketing, hiring or debt repayment that the same £50,000 could have funded. Affordability only asks whether the cash exists; the cost of a choice is the best thing you gave up to make it.
Learn this in the feed Answering from memory, then again days later, is what makes it stick.