I don't know if it is good either, but it is always free from the Gutenberg Catalog. As are most books prior to the 20th century that one is likely to have heard of.
This is a good book, and it's free all the time on Gutenberg. Covers tulip mania, the South Sea Bubble and similar popular bubbles. A catalogue of important human irrationalities. I recommend it.
I don't know if this book is any good, but today, it's free: Extraordinary Popular Delusions and the Madness of Crowds. Some comments in the reviews indicate that this is only a small portion of the complete book.