[grvbck]

> MacOS/iOS/iPadOS were never for sale separately

Mac OS was though. OS X 10.0/10.1 were sold for $129 as an upgrade for Mac OS 9 users. Apple continued to offer OS X as a paid software product up to 10.5 or 10.6 (though it was also bundled with new Mac purchases).

[https://en.wikipedia.org/wiki/MacOS_version_history]