If you want to see the myriad of fakes being offered these days... look on Aliexpress.
You will see a broad spectrum of fake and fantasy coins. Some obvious, some pretty believable.
And DO NOT think they only sell coins with the word "copy" stamped on them like in the photos. That is pretty much just to look honest.
I bought an early foreign coin off ebay that looked very believable. Within 24 hours the seller had the exact same coin listed again. I thought no way could one dealer have two exact coins this old, so I messaged him about it and he asked me how many I wanted. He had like, 20 of them !
I wasn't out a lot of money, but it still burned me up.That's when I started researching fake coins.
Once you look at enough fakes, you can start to tell them from genuine ones.