If there are no boundaries or rule structures, then the incentives often (always?) bleed into some involved party not having a choice, or a Hobson's choice.
Is having an Hobson's choice worse than having no choice at all?
Someone having to choose between selling a kidney or starving is terrible. But the solution shouldn't be to deny the first option - that just leaves starving. It should be to give them a third option.
That said, obviously "no rules" would still be dangerous, but no legal sale is done without any rules.
Yeah, but I think in this case there's an issue where the choosing party lacks the ability to make an informed decision. The risk-weighted long-term medical costs of removing a kidney (in less-than-ideal operating conditions!) and living with just one (probably in an environment where kidneys work overtime due to low-quality resources!) make it a rather expensive proposition. It would've been easier to scrap/work/beg for food than for the potential medical after-care they'll need over time, in terms of the total long-term cost of maintaining their life and/or health levels. But those that understand this are withholding that level of understanding and forcing it to look like a rational Hobson's choice to the donor.
But if one has so little income that he is starving, selling an organ would only postpone the inevitable. You can do this only a single time. As well, this certainly will create perverse incentives.
There's little reason for anyone to submit to organ harvesting to eat. The idea that our society is just enough for individuals to face that choice is kind of laughable.
Of course the best thing is to make artificial organs work, but that's not something most potential organ donors have much influence over.
Someone having to choose between selling a kidney or starving is terrible. But the solution shouldn't be to deny the first option - that just leaves starving. It should be to give them a third option.
That said, obviously "no rules" would still be dangerous, but no legal sale is done without any rules.