As you know, China has become a market for the entire world, and traders are flocking to it from every country, including Arab Muslim traders. Because of this, brokerage companies have emerged between importing traders and Chinese exporters. Most of these companies are owned by Muslims and employ young Muslims who are proficient in Arabic. They act as intermediaries between the two parties in selecting goods, purchasing them, shipping them, and paying the price on behalf of the buyers and collecting the price from the sellers. However, after shipping to the intended country and the traders paying them the price, these brokers start negotiating with the Chinese exporters, exploiting the situation since the price is in their hands and the goods have been taken by the traders. They request discounts or installment payments to benefit from the price based on the discount, or they exploit it for investment if the sellers agree to installments by giving the exporters the option between deferring payment and splitting it into installments over relaxed periods or paying in cash but on the condition of discounting 5-10% from the price, for example. All of this happens without the knowledge of the Arab importing traders. Is it permissible for the broker to benefit from the discount on the price or the installment payments without the buyer's knowledge, given that the discount or installment was only obtained through their efforts?