It's a quandary. Can you offset the cost of the machinery? Or if you go the manual route, can you be bothered to do the graft each time, bearing in mind you will need a decent vice, files etc as tractor alludes to.
My last and only light engineering works near me charges for each setting.. £5 to look at it, £5 to put it on the machine, £5 for x1 x cut, etc,, it mounts up. I use them, but I don't have much choice. But it becomes a pain when a simple turning/cut job gets to £45 plus vat.
WRT to model stuff, I reckon it would be worth it, but it is a heck of a laying on of cash. hmm.
Tenner for a chassis, and you'd have queues. But then you wouldn't want to be messing around prototyping!
A thought; a dimensional database of mazak infected models, cnc on demand out of steel?
Bernie