Books back in those days would have been hand bound, very labour intensive, and if they were leather bound, and goldleaved etc that would have been even more. I have ancestors who were book binders, and the girls in the family were 'book folders' . Then there was the 'goldbeater' who presumably made the gold leaf.
I am having the 250 year old family bible (from another branch of the family) mended by a sympathetic hand binder, and I dare not say what it is costing. The original price is stuck in and if my memory serves me right, it was 3/6, which was a lot in 1760ish. Mind you the binders said that it would have cost less to do just a simple rebinding, but mine is being mended to (hopefully) preserve all the notes written in. I just hope it is OK, but the poor leather book binding was just falling apart. I am hoping this will mean it last another 200 years!!
Helen