If you’re looking to upgrade your e-reader, Amazon just made the transition that much easier. Today the online retailer extended its Trade-In program to cover Kindles and other e-readers. Trading in a Kindle should net you anywhere from $25 to $135 depending on the model and the device’s condition. After entering your old e-reader into the system, Amazon will award you with a gift card for the value of your device. And if you’re about to toss your old Kindle in the garbage over shipping costs, think again — Amazon offers free shipping.