There was (still is?) a French law that mandates the maximum sales price for soft-cover/paperback books: https://en.wikipedia.org/wiki/Lang_Law (if you can read it, the French version of that wikipedia article is much more detailed). The intent behind the law being to attempt to keep "culture" accessible to all incomes, notably by preventing resellers from price-gouging books at the expense of the publisher(s).

This has resulted in many larger tomes being split up when translated to French - for example, the first 5 (English/Original) volumes of A Song of Ice and Fire are sold as 15 (translated to French) books in total : https://fr.wikipedia.org/wiki/Le_Tr%C3%B4ne_de_fer#Publicati...

I am also very disappointed at how often French publishers seem to decide that they can chop up these stories willy-nilly without it degrading the quality of the art (re-)productions that they are selling us.