It has been estimated that a copy of Virgil’s Aeneid cost the equivalent of 160 litres of wine in the Roman empire in the 4th century AD. The Aeneid was an instant bestseller, not least because it had been commissioned and sponsored by Octavian Augustus, the first emperor, himself. It doesn’t matter, the epic poem which was going to be on every pupil’s desk for nearly two thousand years, was an expensive item to possess. If you were on a budget and happened to love wine – and most Romans did both – you would think twice before purchasing such an extravagant object.
In our time, bestselling books are the cheapest. Popularity cuts the price down. It’s always cheaper to make two items rather than one. Of course, unless you’re making a book in the age before the printing press. Then one book is as expensive to produce as the next one, and a bestselling work, although easier to procure, doesn’t necessarily carry a lighter price tag. Developments in bookmaking in the West during the last centuries of the medieval period (12th-15th centuries) saw the emergence of a new economic model for bestsellers. Even before the mechanisation of writing enabled by the printing press, it became cheaper to purchase books – and the more popular a work was, the cheaper it tended to be, not because it was more expensive to make a book out of it, but because the text was more available and the scribes could copy the same text more efficiently.
As universities emerged in the West in the 13th and 14th centuries, the bestselling works were, for a while, university books. It was perhaps the only time in European history when bestsellers were schoolbooks rather than works aimed at a more general readership. But in time, as literacy spread to all the layers of society, the bestseller left the schoolyard to join the marketplace – and the most popular books were also the cheapest ones.