Another newbie looking at first CNC

Hi All, another fairly clueless newbie here considering buying my first CNC.

My reasons are twofold - I've had enough of office work and am considering a career in engineering/manufacturing and my other hobbies include custom computer keyboards and watches, both of which are pretty small so hopefully I can have some fun making them at home. I would also like to attempt a computer case, but don't think my budget will stretch that far...

With your help I'm looking forward to better understanding the criticisms aimed at every relatively affordable CNC I can find when it comes to milling soft metals so I can make an educated choice.

Thanks in advance,
s_o