I actually sent a mail to Udon asking about this book, and they replied that they were just about to finish reprinting and were starting to sent it to sellers again.

Nice coincidence :)

But now it seems that the book is not selling (aside from used and marketplace) in amazon.co.uk.

Maybe it will be coming soon :) (hoping)

@FAUNA bayonetta artbook should be really good, just the environment and character designs are amazing you can check out some of the images here: https://www.flickr.com/photos/platinumgames/sets/72157612359710378/