Ruling on increasing the price of a commodity for one customer over another

Question:

I work in one of the stores, and my sales vary from person to person—depending on the customer's insistence. I might sell an item for one hundred riyals, or I might sell it for one hundred and fifty—depending on the situation and the customer. Is this considered deception?

Answer:

It is obligatory not to increase the value of the commodity beyond what it is worth in the market. There is nothing wrong with lowering the price for some customers below what it is worth in the market. What is prohibited is increasing the price for some customers to an amount higher than the value of the commodity in the market, especially if the buyer is unaware of the prices of commodities, or if he is naive and does not know how to buy, sell, or bargain. Therefore, it is not permissible to take advantage of his ignorance and naivety by charging him more than the known value in the market.