In 2019, George R. R. Martin has published 5 out of a planned 7 novels in the series A Song of Fire and Ice (commonly referred to as Game of Thrones based on the TV adaptation and the title of the first book).
However, when I search for German language translations, it seems that the most prevalent German translation is published by Penhaligon and that the price for a new book is 30 Euro per book and the price for the set is 150 Euro.
It's understandable that book translations would incur additional costs to cover the translator fees, however I'm wondering why there is an approximate 5 fold increase for the German editions especially considering that this book series is one of the most successful book series in the modern era.