Curt Matthews at the Independent Publishers Group provides a cost breakdown on print and ebook production:
Independent publishers are crucial to the vitality of our culture. They are the reason why in America almost no good author goes unpublished.
Curt breaks print costing down nicely, as well as comparing it to eBooks. I would only question his figures for ebooks where he neglects to offset the 50% discount that print books are sold at, making ebook margins much higher (and thus providing an argument (it seems to me) for lower ebook prices and higher author royalty percentages.
My own views on this from an older post are here: http://cacotopos.wordpress.com/2011/06/10/when-the-container-has-no-value/
Have a read of Curt's article - the oft cited argument that upfront costs for ebooks are the same as print books is valid, but this is a fixed cost and for the purposes of this argument can be considered the same for print and ebooks. I'd still argue that where eBooks warrant their reduced list pricing is in the low-to-zero scaling cost of distribution. Granted, there may be a 'stocking' cost for eBooks using DRM, as ongoing servers have to be maintained for managing licenses, but we all know DRM is unnecessary, unwanted, and therefore a waste of money, so I don't accept that as a relevant cost for eBook production.
PS: Curt makes an unrelated shout out to hard working editors while discussing cost. I agree wholeheartedly:
Most books are hugely improved by the editorial process. Nor are the improvements editors make limited to spelling, punctuation, and grammar. Often they are deep structural changes that make a title more engaging for its intended audience, more saleable.