IANAL, but as far as I understand, the OSX license essentially allows running it in whatever way you want, as long as it happens on Apple-approved hardware. Running in a VM is fine, as long as it actually happens on a real Mac.
Depending on how you look at it, the license is either "free" or "not that free, but actually comes with a computer to use it with"
Buy a mac. It comes with the OS. Otherwise, talk to Apple but they probably don't do direct sales of their OS. That might be inconvenient for you but that doesn't change the legal situation that you need a license to distribute binaries that belong to them.
Depending on how you look at it, the license is either "free" or "not that free, but actually comes with a computer to use it with"