The purchase link will send you to a place where you buy a license to use the scenery, not any specific version of the installer. You download the installer from our Products page and, as you can see, there are TWO download links there, named as such:
"Download for FS9"
"Download for FSX/P3D"
This should have been an hint the "FSX" installer, in fact supports P3D as well, and it's like this for each and every product that supports P3D, without having a separate version that runs *only* on P3D.
