Main conclusion from reading the article:
1) Stiff enforcement against organ brokers seems to be key, whether or not organ sales are legalized, since the incentives for organ sellers, organ buyers, and possibly even doctors seem to generally be in favour of facilitating the use of sold organs.
There's also a statement on competition with the international market which I don't understand, I'm looking for a good economist to explain it to me!
"Free health care sounds good on paper, but the problem is that when a country goes legal then it enters into competition with the international market in organ transplant tourism," says Scheper-Hughes. "When the state offers incentives along with a lesser pay scale, but a broker from another country offers slightly more cash without the medical benefits, most people opt for the cash and you run into the same problems you had before legalization."