what organ could be donated while alive
There are many organs one can theoretically do without, or for which there's a backup. Most folks can spare a kidney, a portion of their liver, a lung, some intestines, and an eyeball, and still live a long life. That said, donating a lung, a piece of liver or a section of intestines is a very complicated surgery, so it's not done frequently on the black market. And no one's going to make much cash on an eyeball.