[pliny]

If you allowed people to sell their kidneys the market price would definitely be a lot higher and the trade in kidneys between homeless people and sick people would leave both groups a lot better off. Today you have one group dying in the street and the other dying waiting for a transplant.

[lonelappde]

And if a few homeless people die from transplant complications, hey they volunteered! And now we can stop investing in social welfare because a steady supply of homeless bodies improves the health of the middle class!

The world is not linear, it has feedback effects.