Here is the route I would take, say I wanted to work with Rosetta. I'd get a laptop that was selling used, probably even Win7 or earlier but not too old; a few Thinkpads that by today's standards are way too thick but still have working CD or DVD. They might hover around $50 or $90 or some ridiculous price, but affordable and in a healthy state (cosmetic scuff marks, likable screen, not necessarily top of the line) Linux can be installed on it but in a side-by-side setup like Bodhi offers.Windows will remain there, but BL will slowly become the main OS. A few minutes ago I saw an ad for a $15 chromebook
This will be your main PC/laptop's "stunt double". If you're not sure about some sofware or upgrade, like you wanted to try installing Opera but you are afraid it will mess up your system, your stunt double tries it on first. If it installs successfully, after a week or so, I'd put it on the primary system.
But you will have a backup system now, AND a working Rosetta. A very physical (not virtual) machine that will not be affected by his day-to-day activities) It may have Windows, but so what. I had an XP desktop until that got EOL'ed. I avoided going online since it was mostly for PC games.