Welcome to MobileRead. I'm the official forum meanie.
I just read over your comments on Amazon, and something struck me: You're referring to the iPad as an ebook reader. It isn't, any more than my netbook is one, or my Nintendo DS Lite for that matter. The iPad is a general-purpose tablet computer which can run ebook-reading software, along with many other things. A true ebook reader is something like my Sony 505, which is optimized to display ebooks, not surf the Web, play video games, or follow the stock market. This might have some bearing on the discussion.
Also, you're well-meaning but misguided in thinking that if we pay more for dead-trees books, the publishers will spend more to get them printed on sustainably-produced paper. For one thing, I'm not certain they get a higher wholesale price for a book sold by Fred's Bookshop than Borders, since Fred's is going through at least one layer of distributors, while a company the size of Borders may be buying directly from publishers. But even if that is the case, all they'll do is pocket the extra money. The publishers will make a higher profit, which benefits their management and stock speculators, but doesn't do jack for the rainforests.
Personally, I think it makes more sense for us, as readers, to buy our books cheaply (preferably on electrons instead of dead trees) and donate the money saved to rainforest preservation organizations. It might not do any good there, but it's certainly not going to do any more good in Barry O'Callaghan's pocket.