The waiting list for organ donors is incredibly long. Too many waiting, not enough donors as people who die aren't organ donors. One way to "beat" the waiting list is get someone who is a match to donate directly to you.
However, it's now become profitable that people will "buy" organs to save waiting. It's massive on the black market in the Asian countries. In America, people merely sell them to certain bidders.
Although, with the way medicine is involving, soon we will be able to manufacture "blank" collagenous kidneys that await implantation in the receiving recipient, regardless of blood types.
A liver is worth about $150,000 as well. A heart can fetch you about $120,000. All in all, someone is worth more dead (or harvested) than alive.
