I am using VMWare and have a macOS 10.13 virtual machine running on it. So far it’s been behaving quite nicely, but it requires you to have a decent machine. What I am currently running is Ryzen 1500X, 16 GB DDR4 2666 MHz and RTX 2060. The graphics card is not as important as how much memory you’ve got and the number of processor cores/base frequency for the build times. I dedicate 8 GB of my memory to the virtual machine and 4 of the 8 threads of the processor, so basically the resources are split evenly between the VM and the Windows host. The VM introduces a huge overhead, so any compilation times, etc. are quite higher than running on an actual machine, but it does the job for a smaller project. I am actually going to write a full post here on the forums on how I’ve got it all set up, but for the time being consider it as an option before you go and invest a bunch of money into an old Mac just to be able to compile UE4 games on it. Maybe give it a go first and if it does not work for you go for the better option. 