Depends. How much is it? There a lot of great books out there that are well written that you can buy if you want, I know I have a few, but most are much longer than 236 pages and were cheap..less than $15.
The book you're describing sounds almost exactly like that scam Sold Out After Crisis that contained nothing that 10 minutes of research on Google couldn't provide.
Here's a FREE 509 page manual put out by the LDS church
. Thise guys taking prepping seriously and have WAY before it was popular to do so. They know their stuff.
Any here's a comprehensive list of 80+ different survival manuals/guides that are free.
If you want book suggestions just do a search here and you'll find info on a ton of them.