Most O’Reilly books have extensive previews on Google Books, and that’s true for the Learning Perl 6 preview too. You can check out the beginning of the book. If you like it you can buy the rest. Unfortunately the exercise answers are at the end of the book and not shown in the repo.
The formatting in Google Books is odd and does not look like the print sources (and we have to suffer through whatever e-readers try to do).
Some of my other works in Google Books:
Amazon have used copies available going for £33. How is this?
A new copy costs £42 but will be dispatched in 1 to 2 months.
Something not right?
The book business is cutthroat and dirty. There are all sorts of tricks that middleman play to take advantage of the inefficiencies.
Wholesalers by books at about 50% of the list price then resell them. That’s how Amazon appears to offer such deep discounts. For what it’s worth, I get my royalties based on my publishers revenue, not the book seller’s revenue. So, my cut is off the wholesale price.
Amazon allows all sorts of sellers to move their goods without any organic infrastructure. If something fell off the back of a truck, someone could sell it on Amazon that night. I don’t know if that’s what happening, but the world is a cruel place. It’s deeply troubling when you first find out about it, but this isn’t my first book.
If you buy used books in the US, you may occasionally come by one with a black mark across it’s pages or one with a missing cover. These are remainder books that were reported unsold to the publisher. The publisher refunded money to the bookseller (because there are all sorts of perverse incentives to shift risk to the publisher instead of the retailer). If you bought that book, the publisher and the author probably didn’t benefit from it. More often, I’ve bought books that had previously lived in libraries. That doesn’t really bother me, but the book cost $0.01 and the person made the money on the shipping and handling (about $4 for less than $2 in postage). If there’s a way to make a little money, someone will do it.
I say that you find a company you’d like to support and pay them even if it’s more than you’d pay at fly-by-night places. Otherwise your favorite places will disappear (and that’s against your interests). That’s not because I get more. As I said, my royalty doesn’t depend on the retailer’s revenue.