6. The Chinese Government HATES competition, thus no black market
The Chinese will do what they have always done, sell the organs to the highest bidder, just now when asked they will say it does NOT occur. Any Black market will be undercut by the Chinese selling the organs themselves. Remember an organ is useless with someone to transplant it AND to give the treatment before and after the transplant. That is where the real money is, that is true in the US when organs are always donated, but to get the organ transplanted takes thousands of dollars.
It had to be at least 20 years ago when I first read of Chinese selling organs from executed prisoners. At first the prisoners were executed then the organs were harvested, but the doctors complained of the quality of the resulting organs. The Chinese then told the Doctors, here are the prisoners to be executed, take the organs and then execute them. From what I have read it is a little bit more slick now, but the pattern remains, it is the doctors who harvest the organs from soon to be executed prisoners and after the organs have been removed, the prisoners is "Executed" (As far as I know, they prisoners may be left on the operating table to die).
Side note: The article mentions other sources for such organs, have the Chinese economy gone so bad that people are willing to SELL their own organs, including organs that they need to stay alive??? If that is the case then they is no need to use the organs of executed prisoners, the poor are that desperate.