Looking for advice on budget machine for watchmaking

[JAZZCNC]

You'll defiantly be wanting a small mill or Purpose built sturdy Fixed gantry machine but with your requirements for engraving and aluminium work with tight tolerances plus relatively low budget when it comes to off the shelf CNC you'll struggle to find anything suitable.!!

You'll certainly find something available at your budget but they won't be ideal for your type of work because the spindle speeds are little on the low side with mini-mills and for a decent finish on aluminium/brass with small cutters you'll need 7-8Krpm speeds minimum and for good engraving you'll want 20Krpm minimum most mills will top out at 3Krpm.
Also chances are the mill spindles will have higher run-out and for fine engraving you'll need better than most cheap mills provide.

My suggestion is build a small sturdy fixed gantry machine out of steel so it's very strong, use profile linear rails on all axis with 5mm pitch ballscrews. Add to that Chinese WC spindle combined with Good quality digital drives and you'll have a very capable purpose built machine easily done within your budget. . . . . Any off the shelf machine equally equipped or capable will be 5K minimum.