What is the ruling on the sell-through agreement (بيع التصريف) in which it is agreed that the buyer will pay the merchant the price of the goods after selling them, or that the buyer will purchase the goods and pay their price, with the stipulation of returning unsold items and recovering their price, and in both cases, the buyer determines the selling price?

The first method is permissible, and it is a contract of agency for sale in exchange for a commission on the amount exceeding the price. As for the second method, which is a sale transaction conditioned on returning the goods or what was not sold thereof, its condition is invalid because it contradicts the essence of the contract. However, the contract itself is valid. This can be avoided by promising a non-binding promise of annulment when needed.