There are several pricing options for the Adobe Digital Publishing Suite (as well as the DPS App Builder within the program). A Creative Cloud, iPad only, membership is free, however it doesn’t come with multi-folio options, or any analytics.
Single Edition, iPad only, is $395.00 and comes with more features. Professional Edition is $495.00 and is complete with App Store, Google Play, Kindle Fire, as well as Windows Store options. Not to mention including analytics reports.
The Enterprise Edition, you will need to contact Adobe for a price, but it is incredibly inclusive.