I've been playing with the prices of my books since almost the first day the Kindle came out and was probably the first author to use the 99 cent price. But one of the things I've learned about pricing is that you can't base your book prices on another author's. Different price points works differently for different authors. I have noticed that young adult books tend to sell better at the lower pricing bracket, while many science fiction novels are set at a higher price point. I think it has much to do with the expectations and specific needs of readers. SF readers tend to be very selective in the material they read. Many of them will avoid looking at any book priced low and dismiss said titles as likely poorly written and edited. On the other hand, many Young Adult readers are far more tolerant of editorial errors in books and seem to gravitate to books with a lower price. Don't know why that is. But it is my observation. I'd recommend experimenting with your prices to see where you have the most success selling books. But make sure you allow yourself enough time to accurately gauge the results. If you are changing your book's price every other week, your sales data will be too inconsistent to make much sense of the sales trend. Hence, making it difficult to really know what's the best price for your book.