Where does this eBay seller get his product from?

I found an eBay seller who is selling Fifa 21 Ps4 physical edition for 50€ which is 10€ cheaper than Amazon and overall the cheapest offer on the german market. So far he has sold over 5000 copies. Does anyone know how to get those Playstation 4 games for such a cheap price? Do you think he buys directly from the publisher ?

Blackmarket i think lol