Zac's argument makes an important and tragically overlooked point: there are a lot of people in the world who are "poor" because--to put it bluntly--wealthy elites privilege their own aesthetic sensibilities over the well-being of the least of these among us. We condemn a lot of people to poverty by forcibly preventing them from selling their most valuable assets: their organs.
We can carry Zac's argument a step further by allowing markets in all organs organ-backed securities. Someone who wants to consume the value of his or her organs now might be willing to accept a reverse mortgage: a bank or other firm makes an annual payment to someone and then gets title to the person's organs when they die. There's an obvious moral hazard problem here: I can sign a reverse mortgage for my organs and then destroy them with wine, women, and song, but this can be solved pretty easily by a requirement that I get a regular checkup or that the contract is void if my cholesterol gets too high or something like that.
For the comments: what would a free market in organs (including reverse mortgages) do to the overall health of the general population, and why?
*--I was very happy to learn that Zac is joining an excellent group of colleagues at Western Carolina, which has basically become the George Mason of the SoCon. I expect great things from him.