I was taken aback by the price of audiobooks until I listened to the first Dune book (my first "real" audiobook) during a roadtrip and realized they use proper voice actors, score (admittedly very small) parts of it, and generally have a way longer credit section than I previously assumed. I do wish prices would come down a bit, but I can't say I blame them.

To say nothing of versions where it's just one person reading it straight through, though. Surely those are much cheaper.

I've listened to a handful of fiction audiobooks, and Dune was the only one that I've listened to that had multiple voice actors. I'm sure there are others, but it's uncommon.