Why are you asking another customer who had their own issue almost a year ago? I don't think they are hanging around to help with your issue. Do you have your 1-Click payment options set up on your Amazon account? On the book's product page, is there no 1-Click purchase button? When you say you "click on the book" is that a quick tap from a search result or are you doing that on a book's product page? Are you just quickly tapping, or incorrectly long holding/pressing on a book's icon? Are you outside of US? If so, the hook may not be available for sale in your country. Contact customer service, who can provide real time help. Use the Contact Us button on the right side of this page or amazon.com/contact-us
Paula H., I can't get where you're ending up by using the shopping cart icon to get to the bookstore, but try using the website Amazon.com, at the search block change All to Kindle Store, type in your title and when you get to the product page see if you have any better luck there. If not, or if you want to make that shopping cart route work, contact customer service. In the meantime, do you still have the sample? If so, go to the end of it and a page should come up allowing you to buy it from there. It may take a couple seconds for the page to come up.