The thing is, I wouldn't necessarily class the guy as a moron - please let me finish
He was greedy, certainly. An iPad or iPhone is not essential to survival in the same way that an internal organ is but he wanted one badly enough to go through with it.
But the main thing was that he was astonishingly naive. He thought that the majority of the money, let's say 70% of it, would be going to him. This was his first assumption. He didn't think that organ traders are there to make a big profit - it's a risky business after all, as this adventure has shown. The trader in question is going to want more than a couple of grand if he's going to be risking serious jail time or even having a dead body on his hands.
Then our naive friend forgot about kickbacks - an operation, even an illegal one, isn't just carried out by one person. There are nurses, equipment costs, bribes to ensure that critical bits of paperwork get misfiled, storing and transporting the organ. Again, all of these carry risks and the people involved are going to want a share of the profits.
The final and possibily fatal assumption our friend made was relying on the internet for accurate medical info. Yes, it is possible to survive with one kidney but suddenly losing a major organ causes a massive system shock that *will* damage everything connected to it - including that sole kidney you plan to live another 50 years on, incident free.
He was naive and he was taken advantage of and I suspect that's a buyer's remorse that's going to haunt him long after his new toy has ceased to function. =/