I got scammed by a seller in Mexico from eBay. He had some of what I consider legitimate cards because he had dozens of 'commons' and I bought the Pele from him from the set. That card I still think was good.
We corresponded directly after that and he offered me a half dozen Pele's that I had never seen before that were unique photos, so I assumed they must be real and I bought them direct. I sadly paid good money for them. When they arrived, they were all printed on thin paper and cut off-centered and I figured it was just how Mexican cards were, since I don't have many Mexican cards to compare to.
It wasn't until 6 months later when I was scanning a different card I bought off eBay from him that I compared my scan to others online and realized the cardstock was too thin (I could easily see the card front on the scan of the back, whereas the real cards you couldn't). That was when I started to look at the others I bought more closely and I found identical print marks across two totally different cards/sets and I realized they were all fake.
I was so frustrated! I waaayyy slowed down collecting for months because I felt like it was too risky and maybe I was wasting money
The guy has a bunch of negative feedback from selling vinyl records and cards that people have returned but eBay doesn't kick him off.
Moral of the story: Be very wary of cards coming from Mexico.