I purchased a genuine 12w apple charger from an Australian eBay seller. It failed within a week. I pulled it apart and it was clearly a Chinese knockoff. The creepage between primary and secondary was almost non existent. I told the seller and they were 'shocked'. I pulled apart the replacement they sent, and it too was a knockoff, albeit with better creepage. I told the supplier they needed to take down their Ad as they had sold over 300 of these things. Well after many back and forth emails, they start getting abusive. They just couldn't comprehend that that had broken Australian electrical safety laws, consumer seller laws and violated apples copyright.
The sad thing is, as I did more research, I find out: eBay doesn't give a toss; unless someone has died, the government regulators don't give a toss. So I reported them to Apple,but to be honest, I don't think Apple care that much either.
So this means, if you really want a genuine charger that won't kill anyone, you need pay the Apple tax.