Spreading the idea that organ sales should be legal may the most important thing you do in your life.
I am currently spreading the benefits of organ sales hoping this debate will reach government levels where more countries will consider legalizing some form of organ sales.
I'll start with a most agreeable example: People planning suicide. In countries where medically assisted suicide is legal allowing a person considering suicide to sell their organs could not only save the lives of the people who need the organs, but the life of the person considering suicide as well. Life becomes a little bit more appealing when a person suddenly has tens of thousands of dollars they didn't have before.
This provides a clear and undeniable argument that some people would benefit from selling organs. The benefits for people receiving organs are so obvious I don't need to make an argument for it. Arguments can be made for other the benefits of other people in society selling their organs as well, welfare recipients, petty criminals, and anyone who wants to sell an organ, to name a few. At this point those arguments are not a high priority. Those arguments can be made after the most basic forms of organ sales are legalized. However they might be useful in engaging people in the discussion and bringing more attention to it.
Two countries, Australia and Singapore, have already legalized financial compensation for organs in some way. This idea is not completely outlandish or totally unattainable.
When considering this it is important to focus on the best case scenario, because only best case scenarios need to be legalized.
I would encourage you to continue the discussion in this thread, and spread the ideas other places as well.
Further reading:
https://plato.stanford.edu/entries/organs-sale/
https://en.wikipedia.org/wiki/Organ_trade#Arguments_for_legalization