"The Lord’s manuscripts are daily on sale, and readers read them; buy one for yourself and read it when you have time—in fact, make time for it: it is better to have time for this than for trifles." (Sermo 114B.15)
"Let someone complain, let him grumble, if this Scripture is not proclaimed and chanted throughout the world, if it should even stop being available to buy in public." (Enarratio in Psalmos 36.s1.2)
"Our writings reveal our religion to them, but we are not afraid. Our manuscripts are put on sale in public: the daylight does not blush for shame. Let them buy them, read them and believe them; or let them buy them, read them and laugh at them. Scripture knows how to call to account those who read and do not believe. A manuscript is carried around for sale, but the one whom its pages proclaim is not for sale...Buy a manuscript and read it: we are not ashamed." (Sermo 198.20)These comments by Augustine are striking and indicate a flourishing time in North Africa when the scriptures were widely available and literacy was more wide spread than in previous centuries of the Roman imperial age.
For more fascinating insight into the production of books and manuscripts during this time, read Chapter 2 "The Use of the Bible and the Production of Books in the Time of Augustine" (p. 22-43) in Houghton's monograph. The chapter is filled with quotations from Augustine, Jerome and other contemporary figures that paint a picture of rich scholarship and free flow of ideas and books across the Mediterranean region during this time.
Houghton, Hugh. Augustine's Text of John: Patristic Citations and Latin Gospel Manuscripts. Oxford: Oxford University Press, 2008.