I was surprised when it didn't cost more than a Raspberry Pi.

I was surprised when it wasn't free. It goes against the goals of the device and the surrounding community.

please note that i did not look at the book; so it might be actually worth it's money; but i am a bit biased and the first thing i think once a new pragmatic programmers book hits the market is:

somebody tries to make a quick buck. whatever is in this book, is basically just a quick write-up of what can be found in the internet for free anyway...