Here is a webpage that has a price listing for the organ black market.
The prices of the organs are sold by traffickers to rich buyers who are in need of the kidney. The traffickers purchase the kidney for poor people all over the world. As you can see from the price list, the average price that a poor kidney seller receives for his or her kidney is $5,000. But the average price that a buyer of a kidney must pay is $150,000. The big difference in price between the buyer and seller goes to the organ trafficker. This trafficker must then pay the doctors for performing the operation, and other additional costs.
Still, after paying of his expenses, the trafficker can still make a lot of money from being the middle man in the black market for organs.