So, I could not entirely know before hand if a game is fake or not because resellers are extremely careful with the physical aspects of GB cartridges.
Objectively speaking, OG and legit Pokémon games, mainly the first 3 gens are a RARE thing to find it on steal reselling prices.

I would say that is not that bad in terms that you just want to play & not merely collecting for display (which would be the total L of getting a fake game).

At the very least, I’m thoroughly enjoying my renewed love for retro gaming. It’s funny how it faded with age for a while, but now it’s back, and I couldn’t be happier to reconnect with it.

With this, I'm 8 gens left out of the current 9 of this collection journey ! (I assume that Black & White 2 are a proper gen itself rather expansions of 6th gen, so no need to tell me that there are just official 8 generations so far of main launches).