Let me put a different perspective to this conversation. I have an uncle who had renal failure. My mom his sister donated her kidney to him. He had a renal failure again after 2-3 years. This time they could not find a match within the family. We had a servant in the family. He had the same blood group and he offered to donate. He made it clear that it was not for monetary consideration but he was doing at as a human being helping somebody else. There was an exact match and the donation was done. My uncle is quite healthy now(almost 5 years) touch wood. Obviously the family helped the donor to set a nice shop so that he did not have to do manual labour anymore. Was it ethically right to do this. Nobody knows but at the end of the day everybody is happy.
Now tell me can he be normal can he do normal labour job again no not at all.
If some family members give kidney then I don't say thing about that But selling and buying kidney is to much for me.