Why can't I sell my kidney?

Who is the fanatic who decides that I can't sell my kidney? Why should such fanatics have so much say over my body parts? There are many people who are living in misery, not even able to feed themselves with a full meal a day. Some hungry for the whole of their lives. To these people, to be able to sell a part of their body for $20k or $30k can make their lives so much more pleasant even for a