Earlier quoted context omitted.
What sort of money are we assuming these individuals will get? In your plan is this $100? $1,000? $10,000? With the ratio of the desperate to people who require kidneys, suddenly organs become a buyers market.
Ok, again. Let's play this all the way through. Let's say they get $1. If I choose to sell you my kidney for $1, because i'm desperate and I think that that $1 is worth more to me than my kidney, where do the problems start?
The problems start because 99% people aren't educated on the true value of their kidney.
They are not in an adequate position to judge the value of an essential organ and the ramifications for missing it for the rest of their life. Because they are not doctors and not experts.
It's immoral, because in this exchange exists information asymmetry, where the kidney seller is not informed enough.