My new mac OS won’t allow installing Cubase 7.5. I want to upgrade from that but will I need it installed on the computer to update, or is the Cubase 9 update package simply a complete install? SO that I pay the update prize but get a complete install?
No problems. I also updated from 7.5 to 9. You can download the Complete ISO file after you have bought 9.0.
You don’t say which version of CB 7.5 you have but, if it is a version that is running from the USB eLicenser you will not have to install the 7.5 software onto the mac to upgrade. You just need the USB eLicenser plugged in when you are doing the upgrade to CB 9.
Regards 
Excellent, thank you guys.