Is it permissible for a trader to earn more than 10% profit on goods?
Praise be to Allaah.
The earnings a trader may make are not limited by sharee’ah, but it is not permissible for a Muslim to cheat those who buy from him and to sell his goods at a price that differs from the going rate in the marketplace. Islam teaches Muslims not to seek a huge profit, but to be easygoing when buying and selling, because the Prophet (peace and blessings of Allaah be upon him) urged an easygoing and tolerant attitude in dealings with others.
Fataawaa al-Lajnah al-Daa’imah, 13/92