You don't pay much for this book, but I'm tempted to say that you won't learn any in-depth techniques either. Wendy is clearly very passionate about her subject, and starts off with the basics of mixing primary, secondary and tertiary colours. She mentions that acrylic paint is very versatile and can be used with, for example, impasto paste and iridescent medium to create unusual effect. I was hoping for a bit more on this side of the creativity of acrylics (like how to actually use the aforementioned media and show an example), but that's as far as she went. I discovered that, if you DO want decent examples, a "Google" search is better, as it will get you some "YouTube" videos that are quite handy. It is clear that one of her favourite techniques is mixing shades of green to match the huge variety that exist in the natural world because she goes into some detail on this topic.
In summary, you get what you pay for. Incidentally, the book only cost £[], but postage was £[] because it was sent in a cardboard outer that was about twice the size of the book. So, maybe not such a bargain?