What we can help you buy on 1688
At the hobby end, price tracks rigidity almost linearly, and rigidity decides everything else. Knowing which band you are buying into saves a lot of disappointment.
The honest version: the cheapest machines are excellent at what they are for, and terrible at what they are sold as.
Request a quote for hobby cnc routers
A 3018-class machine on extrusion with a trim-router spindle engraves plastic, PCB and soft wood well. It will skim aluminium with a single-flute cutter, shallow passes and patience, and it will not do it productively.
A heavier frame, ballscrews and a real spindle with a VFD. This is where a machine starts cutting aluminium as a normal operation rather than as a stunt.
Steel or thick-plate frames, profile rail, closed-loop steppers or servos. At this point the limit moves from the machine to your workholding and your CAM.
Spindle, workholding and cutters, roughly in that order. Upgrading the controller on a flexible frame moves nothing you can measure.
If the frame is the limit, no amount of spindle will fix it. We will say when the sensible answer is the next machine up rather than four upgrades that cost the same.
A router spindle in a spare room is louder than people expect, and MDF dust goes everywhere. Enclosure and extraction are part of the budget, not an afterthought.