Step one is to make this cost transparent to people considering selling via Kindle (and to readers who care about this sort of thing). I'm preparing my first novel for sale right now. It's a novel, not a travel book, so I'm basically just delivering a cover image and text so I would expect my "delivery fees" will be much lower, but I didn't even realize that it would be in the realm of possibility that delivery fees would add up to any kind of significant expense. How could I know? Amazon doesn't advertise this anywhere. So we need blog posts like this in order to inform authors so they know that there's strong incentive to look into the other markets.