What constitutes meaningful compensation for an organ donor, especially if the donor is poor and the recipient is wealthy? What examples of human organ sales can find that match or do not match your definition of meaningful compensation?

What constitutes meaningful compensation for an organ donor, especially if the donor is poor and the recipient is wealthy? What examples of human organ sales can find that match or do not match your definition of meaningful compensation? What other terms related to organ sales and donation would be suitable for an argument of definition?