If you own an earlier version of Reason - or a different Reason product (Intro/Lite/Essentials/Limited/Record/Adapted) - you are eligible to upgrade to the latest Reason version at a discounted price!
Below are all the available upgrade paths, depending on what product/version you already own. Click the images, or the text links, to get to the correct Upgrade page in the Propellerhead Shop:
Reason version 1-9.x
Reason 10 Lite
Reason 10 Intro
Balance with Reason Essentials