Who's paying for the new book rates?

Maybe it's just a coincidence, but when I went over to my sales page for Killer Career at Amazon, the price had gone up $2.00.  The book came out in August, so maybe the special deal time is over.
Maybe I'm reading too much into this, but I can't help wondering if the small presses are now funding the big presses' recent drop in prices. How else can they sell those bestsellers so cheap?

What's your thoughts? What about your books' prices? Did they suddenly go up?