Morality aside, there is a reasonably good libertarian argument to make that selling one's excess organs should be perfectly legal. Of course, we expect the government to step in and 'protect us from ourselves' which denies us the right to make that decision in the first place.
Before the hate mail begins, I will add that what happened to this kid is terrible; he obviously isn't very bright and at 14 shouldn't have been allowed to make that decision anyway; he apparently gave up a kidney for a consumer product that will be literally worthless in five years time. I thought it was interesting also that the clinic that did the operation was apparently 'renting' the space from the local hospital, and now apparently the folks who did this can't be traced. Of course, the local hospital administrators and government officials likely get a cut of all organ sales, but nobody is going to work very hard to trace that flow of cash.
I cannot see why people are surprised.
There was a worse story (China Daily - Highlights from the Provinces ) some years ago, of a young couple who had a child and could not support it as they both had no job. They asked the parents to help and found none because they had not accepted the marriage. The couple sold the baby for 4,000RMB. The husband immediately went out and bought................ and IPhone !!
When we are out with our daughter ( 1 yr old this week - yeah - jelly and ice cream party on Friday ) we often get admiring comments to which my wife asks " how many Iphone do you think she is worth." Got to love Chinese humour.
I actually think you may be onto something here so long as were talking about consenting adults who make a full informed decision to sell one of their organs. I do wonder about what sorts of legal remedies governments should make available to enforce contracts to sell organs, though. I think you'd have to limit the remedy to damages and not specific performance.