When I looked, the price had gone to $31. Some of these books have been on the market for some time; this is probably still a good price for someone starting out.
Sometimes, I just browse a seller's items. A year ago, I came across a book I had been looking for for some time; "Spinning Wheels, Spinners & Spinning" by Patricia Baines. The seller had it listed in a somewhat senseless manner, so I just had to see what they meant! Glad I did. It cost me about $5, including shipping. (Yes...FIVE dollars!!!)
Most of my other spinning books were bought when I first started the craft and I was able to buy them right from the bookseller's shelf. Several are now out of print.