That being said, if this increase happened over the last 5 years, that is crazy.
That.
When I played 40K 10 years ago, a codex was £10 ($17ish?). Last I checked they were £30.
In Australia the last Fantasy Codex was $80 a few years ago, and they wonder why people try to get them in PDF from he net. This Book will change every 2-5 years too, depending on whats the flavour of the release is.
That is IN-SANE! Maybe I have been spoiled by FFG, but rules should be "free" and exist to get a player excited about the game and go buy the physical game components. I do understand that a lot of time, energy, and money goes into developing the game rules but such a steep cost to just get rules makes a game stagnant and unable to react to unintended rule anomalies quickly. Phantom nerf for example. Paying that much for something that should be free to download from the manufacturer website is a bridge too far for me.
It is akin to buying a computer program then having to buy patches to fix bugs. No a very customer-friendly business model.