ISBNs used to be free. Now, the ISBN Agency no doubt has financial targets to meet, and they charge: £56.40 for 10! They charge £148.04 for 100, and the price for 1,000 drops to 44p each. All of which seem to unjustly penalise small presses like Leafe. My initial batch has run out, and as I've only published 20 titles in 10 years, it seems daft to purchase 100 ISBNs; but that's what I'll probably do, just because I can't bear to pay £5.64 each.