And for safety-critical purchases...no way am I risking buying something like angle grinder discs or fire extinguishers off Amazon. Fake headphones mean a bit of distortion, fake discs might mean a lost eye.
So now its just low-cost, low-risk purchases where I don't care too much if the item is junk.
On that note, where do people buy electronic hardware if not Amazon/PC World? E.g. for SD cards - Amazon carries the risk of counterfeits, and PC World carries the high street premium.