Many also of them which used curious arts..... Magic arts, soothsaying, necromancy, conjuration, and the like, being convinced of the folly and wickedness of them:brought their books together; by which they had learned these arts; Ephesus was famous for this sort of learning; here Apollonius Tyaneus, in the beginning of Nero's reign, opened a school and taught magic, and such like things: frequent mention is made of the Ephesian letters, which were no other than enchantments; and even Diana, the goddess of the Ephesians, is said to be a magician :and burned them before all men; to show their detestation of them, and the truth and genuineness of their repentance for their former sins; and that these books might not be a snare to them for the future, nor be made use of by others:and they counted the price of them, and found it fifty thousand pieces of silver; which is thought to answer to one thousand five hundred sixty two pounds and ten shillings of our money; reckoning a piece of silver, an Attic drachma; for such might be the silver pieces at Ephesus, a city of Greece, and which was of the value of our money seven pence halfpenny; but if Luke meant by pieces of silver, shekels, according to the Jewish way, See Gill on "Mt 26:15" then the sum is much larger, for a shekel was about two shillings and six pence of our money; so that fifty thousand pieces of silver, amount to six thousand two hundred and fifty pounds; a large sum indeed for magic books!
some manuscripts read "gold" instead of "silver", which must greatly increase the value. Tatian. contr. Graecos, p.