I rather think the massive price drop (99% saving?) is possibly due to the dire reviews... Who knows, this might be one of the many 20p sales they've engineered for Kindle recently. If you think about it, any mark-up on a Kindle e-book is just gravy - the real costs will be the actual books, whereas there are (almost) no production costs for Kindle e-books. It's a strong incentive to buy a big name book before the traditional Christmas book sales.
Yes well it's a bargain IF you had not already paid nine quid for it ! Personally I think it's a disgrace that loyal fans of an author are treated like this as its quite natural to want to pre-order a book but then to find out that your loyalty is " rewarded" by dropping the price 99% is a practice that Amazon should be ashamed of !