SB 5.14.26
kvacin mitho vyavaharan yat kiñcid dhanam anyebhyo va kakinika-matram apy apaharan yat kiñcid va vidvesam eti vitta-sathyat.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
As far as transactions with money are concerned, if one person cheats another by a farthing or less, they become enemies.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
This is called samsara-davanala. Even in ordinary transactions between two people, there is invariably cheating because the conditioned soul is defective in four ways — he is illusioned, he commits mistakes, his knowledge is imperfect, and he has a propensity to cheat. Unless one is liberated from material conditioning, these four defects must be there. Consequently every man has a cheating propensity, which is employed in business or money transactions. Although two friends may be living peacefully together, due to their propensity to cheat they become enemies when there is a transaction between them. A philosopher accuses an economist of being a cheater, and an economist may accuse a philosopher of being a cheater when he comes in contact with money. In any case, this is the condition of material life. One may profess a high philosophy, but when one is in need of money, he becomes a cheater. In this material world, so-called scientists, philosophers and economists are nothing but cheaters in one way or another. The scientists are cheaters because they present so many bogus things in the name of science. They propose going to the moon, but actually they end up cheating the entire public of large sums of money for their experiments. They cannot do anything useful. Unless one can find a person transcendental to the four basic defects, one should not accept advice and become a victim of the material condition. The best process is to take the advice and instructions of Sri Krsna or His bona fide representative. In this way one can be happy in this life and the next.