Adobe InDesign CC 2015 is available as part of Adobe Creative Cloud for as little as $19.99/month (or $9.99/month if you're a previous InDesign customer). Adobe InDesign CS6 is still available for purchase (without a monthly plan) if you prefer.
Adobe InDesign CC 2015 is part of Adobe Creative Cloud. That means you have access to all the latest updates and future releases the moment they're available. Sharpen your skills and master new tools with a rich and growing library of training videos. And Adobe Creative Cloud is integrated with Behance, so you can share your projects and get immediate feedback from creatives around the world.
Note: Now requires OS X 10.9 or later.