Right now, you can get a diode laser engraver on eBay for around $100 USD. That sounds like a deal, but it’ll probably use some arcane proprietary software, won’t be terribly accurate ...
Even a cheap diode laser mounted to an old 3D printer can do engraving, marking, or even light-duty cutting. But what about a laser engraver without the laser? Can that be of any use? Apparently ...