Wirem..
There are many, and many, and many reasons for everything.

E.
Boris S has great results and great stuff at the midrange costs.
Excellent work.

Also.
Endless cheap stuff on china import machines at various levels of cost from 1k-20k abound online.
My own stuff on the big VMC is 99% done and will be functional soon (-again. Version 5).

You mentioned costs:
Technically I would have been far better off buying a carcass and refitting cnc kit of choice.
But that was not obvious at the time 13 years ago, and the one-time major outlays of cash have been spread out.

90% of what people "think" is wrong - on milling steel - somewhat efficiently.
Vastly more rigid, vastly more heavy, is the right choice.
And yes, milling steel is .1% of the people building cnc stuff. Or less.

Costs:
Even then, my servo motors are tiny small nema 23 servos, 400W, 3Nm peak, 3000 rpm, 5000 counts, 60V.
Not expensive, a full kit 290€ including 22% IVA or approx 240€ without tax, landed here in EU.
I import them by box of 10 and sell off some excess sometimes to DIY.

My 2400 kg VMC is very light in terms of double column machines.
Everything depends.
It is also very cheap, circa 45k vs 200k for a similar commercial one.