When a publisher sells an ebook, they receive wholesales not retail price. Wholesale prices in the book businss range from about 35% of list (if you use a full-service distributor) to about 5o% of list (if the publisher sells directly to the retailer). You present an example where the list price is about $28, which means the publisher will get at best $14. But your calculations are based on the supposition that the publisher would get the full list price.

Here's another huge cost you don't include for the publisher with print books -- they are returnable and often get returned. If a publisher gets 25% of the books sold returned, effectively the publisher is getting only about $10 for a list price of $28 / wholesale $14. (Return rates can be higher or lower, but there are always returns.) Using the cost figures you use on your referenced example, the publisher loses money on the print book. And, you omit other costs incurred by traditional print book publishing, including shipping, warehousing books and fulfilling orders.

With ebooks there are no returns (a huge factor in the analysis), no printing, no shipping, no warehousing. Wholesale prices are a higher percentage of the list price. We publish ebooks and get about 65% of list from Amazon, Apple and Barnes and Noble (it's a bit higher or lower depending on which vendor) So it's obvous that our costs are lower for ebooks and the share of revenue we get is higher. In other words, list price of ebooks indeed should be far less than print, and ours are.