There's a free Lite version, if that's helpful. But also feel it's fairly priced given the pricing of most resource/academic style books of this nature.
Zero-budget refers to the tactics and principles involved in marketing a game whilst self-publishing with no marketing budget, and not the book itself if that makes sense.
If the price is a barrier for you, please get in touch, though - can try to help you out here.
Cheers!