There should be a market for organs (both organs of deceased and extra organs of living, like kidney)
Then those who have more wealth could purchase vast amounts of organs and retain them in storage. Therefore, those with more wealth would have control over the supply and demand of organs. The poor man's survival would ultimately be at the discretion of the wealthy. Sounds like a horror film.
The practice would be consensual, as the premise lists a free market of organs. No person would be forced to sell organs without their consent. Additionally, the above argument implies that it is less moral to give an option to alleviate poverty than to continue living in poverty without the option.