Kennyc is absolutely right.
Macmillan has flat out said that it wants to raise prices to $14.99 and this is even higher than the price at which Amazon is currently selling its bestselling hardcovers (
look here to see for your self).
I also really don't get the logic about preventing ebooks from eviscerate hardcover sales. Macmillan gets paid the SAME for for ebooks as they do for hardcovers, so what does matter if they sell more ebooks or hardcovers? Actually, since they get paid the same, they really make MORE money on the ebook because the cost of production is subtancially lower.