I work for a business and my sale prices vary from one person to another according to how much the customers bargain. I may sell an item for one hundred riyals or I may sell it for one hundred and fifty, depending on the situation and the customer. Is this regarded as deceit?.
Praise be to Allaah.
What you should do is not increase the value of the item to more than its market value. There is nothing wrong with lowering the price and making it less than the market value for some customers; rather what is forbidden is increasing it and making it higher than the market value for some customers, especially if the purchaser is unaware of market prices or he is inexperienced in buying and selling and bargaining. It is not permissible to take advantage of his ignorance and inexperience and charge him a price higher than the market value. End quote.
Majmoo’ Fataawa Ibn Baaz (19/108)