Doesn't take a lot of labour hours and overheads to start adding up the costs if you want to make it a sustainable business... that Arc article ends by saying it cost him £2000ish plus a LOT of time to do his X3.

Couple of other thoughts - if you can wait til York uni term starts (mid Oct) then get a computer to control it from the computer recycling people for peanuts. That's my plan anyway!

Might also be worth placing a wanted advert for a benchtop mill on homeworkshop.org.uk and see what turns up?