We purchased Mac Mini Server a decade ago with Server OS X Leopard directly from Apple Business. I made the case to management regarding the server features as opposed to the cost of separate hardware (various decent brands) and licensing of our then (and current) MS applications.
We loved that we could run our own mail server as part of the application (with some other nice features), and a few other useful bits like shared folders, nothing particularly complicated or highly technical as we really didn't need much more.
After some testing and learning in IT, we were ready to deploy for user testing for a period of parallel running.
There was an apple OS update that we applied as advised to keep "secure" against new threats, the next day on switching on, all the "server" functions had gone. Just like that.
Enquiries revealed that despite purchasing the OS as part of the unit, it was no longer supported, we could re-purchase the "app" for a tiny sum but no guarantees from Apple that it would remain supported or not be withdrawn at a later date (and in fact all the useful features such as mail server have since been removed from later versions). They were very coy about it but had a compensation scheme to give you back the value of the app ($20) but only if you were registered in the US. UK (and presumably other) customers were very much "not first class citizens".
Had we gone live, been through the testing period and completed the transition it could have wiped us out as a small company.
Their attitude was that we could now purchase the functionality from 3rd party vendors, putting us back to the sort of costs we had with MS, and a complete inability to do this in-house.
(We'd have purchased about 30 seats of hardware, along with portable devices in varying numbers had this worked, plus another several hundred seats after a later takeover that expanded our footprint considerably, along with other hardware, but I guess that's still not even small beer for them. Users still resent the windows phones forced upon them later....)