I used to buy a lot of books in Amazon, but the paper and printing are worse than the physical store, which is acceptable. After all, the cheap price is there, and people have to make a fuss about paper.
The most important thing to note is that its books do not have 100% guarantee that every book is genuine and authorized. I bought a pirated book once, just like the one sold at the stall. I'm bored. I haven't bought a book for a long time. But there is no place to buy books, and I have been patronizing recently.
In my opinion, if you want to avoid buying pirated books on Amazon, don't buy some books that are too obscure, because those books are not published by regular publishing houses. If you look for it, it will give you books from underground publishing houses. What I bought at that time was a Feng Shui book. It's like eating in a restaurant. Never order dishes that others seldom eat, because few people patronize these dishes, which are either bad or moldy.
The above personal views.