I doubt money is the limiting factor for book uptake in the West, particularly in towns with a library. You're instead selecting for curiosity, intelligence and attention span. (Say this as someone without enough of the last.)
There's something deep about this commitment, and I think we would get almost the same result if we had digital devices that were made to hold exactly one book, and you had to take yours to the library/store to return the old one and download a new one - such that even if the cost of copying the bytes is zero, you pay the cost of physically carrying that one book that you took the time to pick out.