Is original BOI not available on steam?

Hi guys, so i own the original game (non-rebirth), as well as repentance. And recently, the older game went on sale, so i wanted to buy it for a friend to check out, but for some reason when i go to the shop page, it just says that it isn't available in my region, even though i bought the game like a few months ago??? I live in germany, but since rebirth isnt banned here, why would the original BOI be banned? Or am I missing something? Is ther any way i can still gift him the game?
Thanks!