Think again.
Inspection copies are meant to go to lecturers with a view to recommendation for student purchase. As this is a monograph currently priced at £50, this text would not be suitable and therefore an inspection copy is not applicable on this occasionInsanity. Perhaps it didn't occur to them that charging £15 per copy might lead to lots of sales. Instead, academic publishers are relying on a very small number of very expensive sales to libraries. I've paid £55 for books quite frequently, and regularly see editions sold at £125, £150, £250 and even £600.
In an era of open scholarship and democracy, this is an insult. I feel sorry for the authors, whose work is destined to be read by a tiny number of people, and I feel sorry for a readership denied access to a fascinating subject. The publishers are lazy and greedy. They've got rid of indexers, editors, proof-readers, and now they can't be arsed to promote what they publish. I'm certain that this book would appeal to enough readers to be viable at £15-20, but that's too much effort. Perhaps they'll say that ther readership is so tiny that decent pricing is impossible: a) not with this title and b) perhaps you should consider your publication choices.
This kind of pricing is a tax on scholarship: without publishing a book, publicly-funded academics don't get REF points, promotion, professional respect, funding and so on, so we're forced to hide our work away when really we want everybody to read it. It's the opposite of what we should be doing.