See this blog post by Michael Stackpole on the subject.
http://www.michaelastackpole.com/?p=1287
There are some editors and publishers who get it. However, if they work for a big conglomerate, sometimes the accountants and lawyers get in the way of rational thought.
On the other hand, in the cost analysis, you're missing the cost of servers, bandwidth, DRM, and handling credit cards. Servers and bandwidth should probably be covered by regular overhead costs since most publishers have a website, but it is a cost of selling ebooks that is not negligible. Yes, DRM is bad, but publishers (or maybe it's their accountants and lawyers) need it and I've read somewhere that it costs a lot.
