Thats the problem with ebooks, with regular books you can always find a used book cheaper but that doesnt exist so you're always paying retail. it just doesnt make sense. There are too many old coots in the publishing industry to tell the difference between different formats and adjust prices accordingly.
I think they think too much in the old economics way of if an ebook costs $4 (which is what it should be because there is hardly any costs besides the author and a server) then everyone will shift from regular books like some sort of pricing disparity but the truth is most people wont because a) some people just love hard cover books and b) reading on a computer is a fast track way to go blind and c) ereaders cost and arm a leg and your first born to buy for most people (especially with the current economy, you can't even buy rice wholesale anymore because of food shortages what is this 1929??). Until someone can come in and strong arm the publishing industry Apple-style, we will be stuck with the $25 4 year old ebook while a used hardcover is sold for $8.