You really should never be shopping on Amazon for high margin products that are easy to fake. This means perfume, cosmetics, sunglasses and name brand clothing. These items are cheap to manufacture (even the real ones), but get their high perceived value from brand. Those Raybans you love? A $250 pair costs Luxotica around $5 to manufacture. So items like these are common to fake because the fakers can often get a product that is close in quality to the real thing. If they can just trick people into thinking it IS the real thing, they can make as much margin as the big guys without the cost of building an actual brand.

BTW, because of the way Amazon’s FBA service works, even ordering items that are “sold by” a reputable retailer but “fulfilled by Amazon” gets you a high chance of receiving a fake. This is because they mix FBA stock and don’t discriminate what stock it comes from when filling that item, regardless of who the seller is.