Does a best-seller book author make more money if I buy a book at full price?

No. By the time the book is at the retailer the publisher and author have already been paid their share. Whatever price the retailer ultimately decides to sell it at, whether it’s full MSRP or $0.01, does not effect how much the author receives.

It would probably depend on the contract the author has with the publisher.

No. What @Darth_Algar said.

What you call the “list price” is the suggested retail price. It is sometimes listed on the book, and sometimes listed on the invoice to the bookseller (along with the discount that they receive), and sometimes neither. No one is under any obligation to sell the book at that price. Some bookstores can and do sell above the list price, and some sell below. Note that the price printed on the book (when publishers do that) is often determined over a year before the book hits the shelves, and this can wreak havoc in other countries (like Canada, where I live) when the dollar fluctuates on a much shorter timescale; the retailer takes the brunt of that decision when the dollar declines. Printing that price on the cover is a stupid practice, and I wish publishers would do away with it entirely.

@Darth_Algar is correct in that the author’s book deal is independent of the book’s list price. But having a great many unsold copies when buyers lose interest in the title (this is where remainders come from – those pyramids of $5.99 hardcovers) is bad for the author’s future relationship with that publisher, and vice versa.

However, @Lightlyseared is also correct in that author contracts can contain royalty agreements for copies sold, but as far as I know this does not vary with retail price, either. Authors commonly also receive royalties for things like e-book sales and library photocopies, again depending on their contracts, the appropriate copyright law, and the policies of the publisher.

So, the answer to your question is no, there’s probably no direct effect whatsoever of buying your undervalued copy of this book from Amazon. However, this kind of practice has and does have indirect effects on your author by forcing independent retailers out of business, whether it is done by an online-only retailer like Amazon, or a big-box store like Costco or Barnes & Noble. Enjoy taking advantage of deep discounting today – the repercussion is a less diverse and less knowledgeable bookselling environment, which ultimately results in a less diverse and dumbed-down publishing environment. It’s contributing to a much bigger problem than whether one author gets a few cents more or less from your purchase.

http://boingboing.net/ is a site run by authors and they report some of the skullduggery they encounter in the book business.