This is a matter of great discussion in the transplantation world worldwide. What are incentives, are they really unethical, and can you look at them in certain ways? Can we look at disincentives rather than incentives? It's very complicated. It's extremely complicated, so your question about whether it is ethical can't be answered in a simple way.
There are many things, though, that we can do to remove barriers and obstacles to transplantation. Is it ethical to make a living donor pay for their own surgery for this system, which will save the system thousands and thousands of dollars by the individual recipient having received a transplant? There are many ways that plays out through this entire process.
Do you want to add anything there?