Virtualized iOS builds at Shopify
engineering.shopify.com
engineering.shopify.com
The only 2 use-cases I can see for virtualised macOS are remote development/test machines, to which their answer would be "buy a real, local, Mac", and for continuous integration, for which their answer is currently fuzzy, but their acquisition of BuddyBuild makes me think they are likely to launch some sort of CI for developers in the future.
I don't like having to run, maintain, and rack physical Macs to do the same for iOS/MacOS projects. It's a pain.
I was unaware of the BuddyBuild acquisition! I hope that helps in the future.
Quite a lot I expect.
(Assuming US salaries, benefits, taxes and any related costs such as office space, equipment etc.)
But I'm probably biased as I spent 4 years of my life building and running a company that built a cloud based CI service for iOS, so that others wouldn't have to..