My grandfather had a lot of books. They were kept in a made-to-measure bookcase (which I still have) and contained volumes of novels, books on (military) history and an encyclopedia. The last one consisted of two volumes of the Larousse Pour Tous published by Claude Augé.
I don't rightly know what these old volumes are worth (something between 10 and 1,500 Euro, according to the sites I googled) but to me they were - and still are - a source of knowledge, even better that a computer.
Although in French (my grandfather was born in Wallony) I could understand quickly what was written there. I must have taken up French without realizing it. As I was fascinated by history, I could spent hours browsing through the Larousse, researching information for something I was writing at that moment.
Do you have items you cherish?