I'm in a very heavy library family; we are checking out and reading a few hundred books per year between all of us.
Yet we still buy a few books, and I bet that if we made an inventory of the books we currently own that are in the house, it would number in the hundreds. But... most were purchased secondhand. I take my daughter to the bookstore every few months; it is always busy. While she is browsing, I also look around. I'd buy half a dozen or more books on each visit if it weren't for the price. At retail price, books aren't a good deal. Even buying a paper copy of a public domain book will run $15-20. Why?
The US prices averages out to ~$15, while the Japanese prices average out to $10. You might say most of that is due to the current exchange rate (1 USD = 154 JPY), but then most books listed on Amazon Japan's "novels" best sellers seemed to be priced around ~$6 USD (~900 JPY), compared to the $18-22 in Amazon.com's "literature and fiction" list.
Did you mean page count? For the novels I read, 200-300 per volume seems common. This seems comparable to the English novels I have, so it feels like less money for roughly same amount of content.
Because many light novels come in series that are spread over several volumes, it's arguable that it costs more money to finish a story because you have to read all these volumes instead of one monolithic tome. I buy the volumes one by one as they are released and don't feel that the individual books are that expensive, but someone catching up on an old series might feel different.
If you mean physical size, the average English books does seem physically larger than the average Japanese book.
Everybody needs to get paid, and everybody needs to make a profit.
The folks that store the books (think Wholesale), the movers/couriers, the retail that has to pay rent/employees/etc _and_ make a profit.
The consider that (depending on the country) there is a VAT on that book. It slowly adds up.
I remember in Brighton back in the 90s I had found a second hand bookstore, that had 5x the books per sqm comparing to the Barnes & Noble in the center of London. B&N had wide corridors, the shelves on the perimeter were all the way to the ceiling, but the non-walled ones were 1.5m high. And considering that they wanted the books to look cool, they were nicely spaced.
Now when you compare this to the second hand bookstore, where presentation is not 'a thing'.. you got many-many more books per sqm, and the authors/publishers don't need to get paid again. But still.. a second hand book will always been 1/3 to 1/4 of a new book (from own experience).
EDIT: I sometimes think that if my life takes a very dark turn, and for whatever reason I end up poor and alone, I will find the smallest/cheapest possible village that has a public library back to my country of origin, and I will be spending max amount of hours in that library.. free wifi, free heating/cooling, and ALL the books I can read(hey, my name is Henry Bemis after all!!)
Off-topic, but wow there were some good used bookstores in Brighton. I think I know the one you mean, but the quirkiest was the one with a massive pile (literally a pile) of unshelved, uncategorized books in the basement. Hardbacks were £1, paperbacks 50p. It smelled faintly of mould down there, and there were some chairs and beanbags (the beanbags were too dodgy for me to sit in, lol) around the edges, so we'd sneak in cans of beer and spend the afternoon going through the pile and reading what we found. Once or twice the owner shouted down the stairs that he was going to the pub and to turn off the lights and make sure the door was locked when we left.
Sometimes I miss being young and poor. I'm not sure I'd enjoy spending a day like that anymore, and I'm not sure why.
Yet we still buy a few books, and I bet that if we made an inventory of the books we currently own that are in the house, it would number in the hundreds. But... most were purchased secondhand. I take my daughter to the bookstore every few months; it is always busy. While she is browsing, I also look around. I'd buy half a dozen or more books on each visit if it weren't for the price. At retail price, books aren't a good deal. Even buying a paper copy of a public domain book will run $15-20. Why?