Complete Rubbish
'many times by authors and publishers and God knows who else ad sodding nauseam - the actual printing cost is probably the smallest proportion of a book's production cost'
I would love to know which authors said this. Having worked in the publishing industry and is married to somebody that still works in the publishing industry. Authors usually hate their publishing house and call them among other things blood sucking leeches.
Maybe you are mistaking talented authors with the advances paid to celebrities to allow a ghost writer to string them a book together for the unwashed masses. They are not the same thing
Most talented authors now Write and Publish in electronic formats which are then emailed to the publishing house in a pre-approved format. The publishing houses arrange editing, printing, distribution, PR, Press Releases... blah blah blah.
Editing and sundries are back charged to the author. That is why when an author signs a deal for £100k they end up with a cheque for £20k because of all the back charging which goes on from their benevolent Publishing houses.
Charlie Higson once said the only money to be made in writing books was getting them on telly. And he's written a few best sellers so I would imagine he would know.
So where does all the profit go?