I had saved up a bunch of silvers to buy some books with but the cost of books is way up since last duskruin if you can even find someone selling them. :-(

Even so, I would expect the cost to be going up.
It is possible for a 100-ticket book (keeps the math easier...) to generate 31,000 scrip now even for a single combatant (not on a trio group run, for the boost), so I would expect that to go for 30M plus.
Or 15M+ for a 50-booklet.

I would also wager that most, if not all, that sell books for silvers participate in the silvers for cash market on some level. With that market in steady decline with nothing upcoming to even temporarily reverse it, there's going to be a lot fewer willing to sell books or BS for silver.

Please note that my acknowledgement of that market in no way implies that I support it.

Starchitin, the OG

A severed gnomish hand crawls in on its fingertips and makes a rude gesture before quickly decaying and rotting into dust. A gust of wind quickly scatters the dust.