The 4th edition authors included brian d foy, who said "I think Tom [Christiansen] and I worked for about two years to produce the current edition. I certainly wouldn't want to spend that much time again to make less than $1,000... It's a huge effort from the editors and proofreaders and the book won't sell enough to make back the effort they put into it." https://www.reddit.com/r/perl/comments/1ns5r9n/comment/ngmvt...