order dropshipping

The client has a B2B sphere. He really liked the idea of a LC for dropshippers. But we need to propose a solution to the following problem. For the drop, they have a certain price for goods. When Drop places an order, for example, for a T-shirt, its cost is 100 UAH. he says that you need to specify such a price when sending products, for example, 250. They send the order to the end consumer, receive an overlay from the new mail, and here it is necessary that the system automatically accrues a bonus of 150 UAH to the drop and, having entered the payment report, they understood how much they should pay drop in the end for all orders. How do I set this up automatically if the price of their items is different and the drop markup is always different too?