Is this morally wrong?

[Larz60+]

I there is someone who invest time to write a book, it's his decision to take money for this book or not. We have to respect this decision. If there is someone who made it for free, we should spent money to show him, that his work is valuable.

I think this applies to those who ask very low prices for their work. Mike Driscoll comes to mind, most recent book 'ReportLab' only $14.99, and offers all 4 of his books for $29 and often for free.