The Merchant and the Undercutter.

The case: A cloth merchant in a busy market town finds his rival selling the same bolts at a loss. Week after week the rival lowers the price, bleeding his own treasury to draw away the merchant's customers. The merchant comes to me with a ledger in his hand and asks: do I match him, or do I starve him out?

The sutra:

जो अपनी ही नाव छेदकर दूसरे की नाव डुबाना चाहे, वह पहले अपना ही किनारा देखे।

Jo apni hi naav chedkar doosre ki naav dubana chahe, vah pehle apna hi kinara dekhe.

Meaning: He who cuts his own boat to sink another's should first look at his own shore.

The principle: A rival who sells at a loss is not competing with you; he is burning his own grain to keep you from the mill. Do not join that fire. The man who harms himself to harm you has already lost twice — once in his treasury, once in his judgement — and a man who has lost his judgement will soon lose the rest. Your task is not to fight him but to outlast the season of his folly.

What I would do:

First, count his losses, not your own. Estimate how long his treasury can carry this. A man selling below cost has a fixed number of days before his stock, his credit, or his patience runs out.

Second, hold your price and widen your ground. Keep your honest rate, but add what he cannot copy — a guarantee of the bolt's weave, a promise of return, a steady hand at the counter. Let the customers see the difference between a man who sells cheap and a man who sells true.

Third, when his boat takes water, be ready at the shore. The day his prices rise or his stall empties, the customers will come back. Receive them without a word of triumph. A merchant who wins by patience, not by rage, keeps his market long after the undercutter is gone.