US pricing for the paperback is $7.99.
If you’re really worried about price though, the Kindle edition is a bargain at $2.99 (or the equivalent in pounds or euros). Interestingly, I make a bigger royalty on a $2.99 kindle edition than I do on a $7.99 paperback.
That makes it hard to see how traditional publishers can justify asking almost as much for the Kindle version (and sometimes more!) than for the hard copy. e-books should be considerably cheaper, not only because they are much cheaper to produce and distribute, but also because they are more restrictive (you can only lend them once ever, if at all, and you can’t resell them) which ought to mean more sales. The disruption of the publishing market has really only just begun.