Cheap, laser and metal cutting are not normally seen in the same sentence...
You'll want a beefy fiber laser and an industrial setup with regards to fume extraction, metal vapor isn't exactly healthy to breathe. Operating a machine of that power level in or near a residence is probably not the best idea unless you live remote. For work like that I'd probably outsource it, I do not have enough metal cutting projects that I need that capability in house and in an extreme case I can always break out the jigsaw (or even the grinder...) for a one-off. Not quite as precise but for most stuff I do that would be good enough.
Depends on your definition of "cheap", but a Shapeoko handles light cuts in aluminium very well. Cheaper routers are readily available on Aliexpress if you don't mind tinkering.
Plasma cutting aluminum has challenges all its own.
Hydrogen production for one (you can imagine where that's going :) ), and you'll need some shield gas to make it work reliably. Cutting speed is going to be pretty impressive, edge quality not so much compared to a laser.
A pain to get that DYI keyboard plate (no, I don't want to use a PCB).