Not that surprising if you consider that books before the Gutenberg printing press were artisans work of art that required years of work of specialists.
In other words: Today some of those will cost more than a Ferrari to make. They use Vellum paper that is much better that today's but require killing hundreds of animals each.
Only very rich people could afford that. I had access to European books collections of the 16th that are in Color, much much better than any normal book we have.
If you think about that it is normal. Color require more printing plates in a printer, but just changing your ink if you do it manually.
> They use Vellum paper that is much better that today's but require killing hundreds of animals each.
Yes, but also, it's more of byproduct. You raise sheep for wool, they're going to lamb every year, you eat most of the lambs, someone buys some of the skins to turn onto vellum.
The processing to produce vellum would be expensive, and not something every shepherd would be making at home, but the input sheepskin would be plentiful.