The ruling on the Profit of the Product being more than Half
Question :
Is it permissible for me to earn on my sales product more than half in profit since I pay the rent on the business location and I pay the employees?
Answer:
The custom is that the products are sold according to what is equal to it in the markets and with the merchants. It makes no difference whether the profit is a lot or a little or there is a loss. However, if there is no customary price, it is better that the salesman be moderate in taking profit according to the amount of rent he pays, the salaries of his employees and the amount of profit he gets after all of that. It should not be an extremely large increase that would harm the buyer who is unaware of what its equivalent value is.
Source:
Ash-Shaykh Ibn Jibreen
Fatawa Islamiyah, Vol. 4 Pages 386-387