Official full installer downloads for Mac OS X Mavericks 10.9 are no longer directly hosted as standalone files on the Apple Support
We do not host or provide the download links for Mac OS X Mavericks 10.9 ISO and DMG image files. The links provided are from third-party sources and are subject to change. We are not responsible for any issues that may arise from downloading or installing the operating system. mac os x mavericks 10.9 iso and dmg image download
However, that "free" label is exactly why finding a clean Mavericks ISO today is difficult. Apple’s servers no longer host the installer prominently in the App Store for older machines, and because it was never a paid product on physical media, there are no official DVDs to rip. Official full installer downloads for Mac OS X Mavericks 10