It's about that time of year, time for all the back-to-school sales to start up. And Amazon has just started theirs today for the Kindle Fire HDX line of tablets. These are the 7 and 8.9-inch LTE and WiFi models. You can buy them from the link below. The Wifi models are between $30 and $70 off, with the LTE models being $100 off (for both AT&T and Verizon).