well I must admit, I did not study the whole problem, but personally I don't mind paying a bit more for a physical version (especially if there is a beautiful collector edition !!). Even if, sometimes, I buy digital versions, I do prefer a physical version with a beautiful box and goodies than just a digital version, even if I have to pay a bit more. About localization, well in a general way, it is not always the publisher/distributor's responsability. I don't know what Larian decided about D:OS but you usually have different languages EVEN on the digital version meaning localization impact the price anyway !
About the book example, I cannot read on an ebook, I don't like it so I still buy paper books. And I'm not the only one so bookstores will still have few costumers

same same with the video game