I DIY built a CNC cutter in the year 2000,,
I do not think there were any small machines to buy at the time,, only big industrial units, in the $XXX,XXX price range,
I purchased a lightly used version of a CNC knee mill that did not have a milling head,,
it even included the "computer", it ran on punched paper cards,,, so, you can guess how old it was,,,
then, I purchased a PC operated control and two stepping motors from one of the only places that sold them in the year 2000,,
My total cost to get the machine running with an oxy-fuel torch was right at $5,000,, and about 40 man-hours of wiring and setup.
the plasma was added about 3 years later, at a cost of $3,600, I bought a REALLY high amp ESAB machine torch unit.
That plasma torch could cut 3/16" steel for 60 hours of torch "on time" per set of consumables.
The machine was cutting at 60 inches per minute,, it made a LOT of parts per set of consumables,,,
The oxy-fuel torch probably ran 300 hours of torch on time per consumable,, that torch cut at 20 inches per minute,,,
That machine produced production level quantities of parts 8 to 10 hours per week for 12 years,,,
My consumables, and replacement parts were less than $1,500 for the entire 12 years I ran the machine.
I never tried to learn to import a drawing by scanning, I produced everything with G-Code,,,
If I were to try to sell "one-off" custom parts like a sign, I would have lost my shirt,,,
my parts were all repeats of previous parts,, so, I called up a program, loaded a piece of steel, and hit the go button.
NOTE, I did not include the cost of oxygen or propane in my cost estimates,,