[Arguendo]

He is not an admirable person, but when the government tries to kill off a trade that is valuable to both parties, unsavory characters invariably create a black market to fill in the gaps.

Why would a legal organ market be so bad? Conservative economists such as Gragory Mankiw support it. It is an area where demand significantly exceeds supply because market trades are prohibited, with deadly consequences. Allowing people who need money more than they need an extra kidney to sell one of theirs to people who badly need a kidney would be beneficial to both parties.

[hedgetrimmer]

when the government tries to kill off a trade that is valuable to both parties, unsavory characters invariably create a black market

So all trade is good, when two parties find it valuable? I guess that's why slave labor is making a comeback.