Thanks for all the comments guys. It's really surprising to me to see so much activity on the book in general.
For the record, I have zero control of the price. When brought up to the publisher, they thanked me but said they will price it how they feel it should be priced.
The best I could do realistically was get the 20% off coupon and provide it to those interested.
From the standpoint of the book's contents, it really depends on what you are looking for. It is intended as a start to finish guide, so yes, there's a lot of basic stuff in there (the first 5 chapters, honestly, are very elementary for most users barring the part about building realistic terrains).
I'd say for advanced users you're going to find the most information in three basic sections:
1) My two chapters on optimization and testing, which comprise a large chunk of the book. There's really good info in there and a lot of time went into those two in particular.
2) The AI stuff. I'm an AI geek, going way back, so deconstructing the methods the AI used to navigate were important to me and finding workarounds using the existing system was also important. Topics such as floor zones, cover, waypoints are all covered.
3) The addendum/references. I literally went through every single error code I could find and put together a list of 'what could cause this', every Lua code is addressed (borrowing heavily from my previous work on the Lua API), every FPE file setting, every functional gunspec setting. This entire section probably comprised the last 25% of my work on the book before the dreaded proofing and typesetting stages.
There is a HUGE amount of info in those sections.
If you want a good example of my work, one chapter I started after the book finished that I just kind of let lie as a rough draft is available here:
https://forum.game-guru.com/thread/220802
I'll believe that you'll see that it's a fount of information that literally NO one knew before. Granted, I still have more to add to it, like the dang files and I still run into weird issues with it, but it's already gotten several users on their way towards custom projectile usage.
Thanks again to everyone for the interest. For the record, the bulk of the files (barring the cybernoir assets which are still being finalized with some finishing touches) are available here:
https://www.crcpress.com/An-Introduction-to-GameGuru/Messina/p/book/9781138612631
Specifically under 'additional resources'. And yes, I am aware that anyone can download those. Some of the resources were generously donated by members of the community. Some of them are my own resources available on the store. There's a ton of maps and the like to help you along though most of them are based around being able to reference them from the book