But the question in this meme (which has other iffy ones as well - we're all responding to the book thing in part because that caught my eye in the first place) is about having a collection of books, owning books, and that does speak to economic luxury. If you assume that owning books is a luxury, that is.

There is another aspect of social - not economic so much - class that isn't addressed in this meme, and certainly colors the book thing. People who don't have the money for a lot of luxuries may still own books, but I think we as a society do consider those folk of a different "class" than those of similar economic standing who wouldn't prioritize art or reading. Artists, for instance, Teachers living off a single income. And yes, there's definitely an element of classism in that.