I'm particularly irritated with the distasteful attitude the author took when he was mad a couple of hacker news readers didn't think it was fair to charge $0.99 for this.
Hacker News readership can be a tough crowd, but I wouldn't want to have it any other way ;) Thoughtful comments (i.e. where the reader took the time to do a little bit of research before commenting) make it all worth it.
http://news.ycombinator.com/threads?id=vais
Didn't sound like a distasteful attitude to me. Just believes in his own work.