I recently helped a friend setup Logic X with his (older) iMac. I don’t remember seeing any such option on the App Store. He paid, the app downloaded, and *then* he was informed that he had to upgrade to High Sierra. He did that, and after that Logic Pro 9 would no longer open. It had become buggy as hell on the OS he was running previously anyway. I think the last OS that works well w/Logic 9 is Snow Leopard.
Apple really just wants to keep funneling users towards purchasing the latest software (and by consequence, hardware).
Thanks for your reply,
Thats a drag for your friend. I am running Logic 9 on El Capitan and all works great on my end. Decided to stay put for now since it works great for my needs with the Xtouch and extender,