Turkey has a trickster character named Nasreddin Hodja. There are a number of tales told about him. Often he achieves a standard of justice in a humorous way. I went searching for a Hodja tale about business ethics. Didn't find any, so I wrote my own (okay, so this borrows from the Irish tradition):
Nasreddin Hodja was poor in those days, so he went looking for a job. The local mosque needed a tiled path, so he offered to build one for a gold coin. The mullah accepted his offer. After he had built the path, the mullah gave him a silver coin. Hodja accepted the coin grudgingly. In two months, the mullah came back to him, saying "Oh Hodja, your path is so beautiful we want another one. We will pay you another gold coin." Hodja said "Fool me once, shame on you. Fool me twice, shame on me."