Getting fake or low quality garbage from Amazon has made me stop using their product most entirely. I have 0 faith in it and I will gladly pay the inconvenience of driving or 5-10% more for a retail store brand.
There's some percentage of people that always want to pay the lowest price and if the product turns out to be fake they return it. Say you order 100 things over a month and 5% turn out to be fake the only cost is time (Amazon pays for shipping if the product is fake I believe). That's compared to paying 10% more on every product plus the time it takes to go to the store.