On DTRPG pay what you want..
The Core rulebook and two solitaire adventures for The Dark Eye..
https://www.drivethrurpg.com/product/185074/The-Dark-Eye--Core-Rules
https://www.drivethrurpg.com/product/192953/The-Dark-Eye--The-Vampire-of-Havena
https://www.drivethrurpg.com/product/290858/The-Dark-Eye--Conspiracy-of-Mages
There may be more freebies in Ulisses-Spiele's catalog, aside from the Quick Start Rules which you may not want since the Core book is free, but these were the notables.