How is that extortionate? Using the inflation calculator of the Bank of England that is 86 pounds now or $110. Admittedly that more expensive than the current price of $24 for the paper back, but at worst that seems to be twice as expensive as a common price for a 850 page book?
At October, 1970, the provisional figures of average weekly earnings of full-time manual workers were £28 Os. 11d. for men aged 21 years and over, and £13 19s. 10d. for women aged 18 years and over. Between October, 1965 and October, 1970, average earnings of all workers covered by the regular inquiry rose by 45.9 per cent. and the general index of retail prices by 26.4 per cent.
https://api.parliament.uk/historic-hansard/commons/1971/jan/...
So it would have been around a decent chunk of your weekly wage as an average worker, it sounds like. I think what we would need to know is how much excess income someone would have for something like that at the time.
Consider that some technical books have a potential target audience of thousand or so people. Then ask how many hours the book needs to save you to be worth $100. Depending on the book that can look very cheap.
Oh I forgot that's a thing in some countries. I did both of my university degrees just borrowing books needed from the library, they have to have enough copies for every student if needed.
Most of the time we'd end up with a group of friends where we'd each buy a different book then share among each other. Not many were spending the whole amount every semester, especially past the first year when we didn't really know any better.
I think I paid similar for Wolfram's A New Kind of Science back in the early 00's. Huge great beast of a hardback tome, promising the secrets of the universe. I don't think I ever finished it, and ended up giving it away to a charity shop after schlepping it around the world with me, unread.
