Looks like it may cost around $20k+ to make it actually into a CNC or maybe not - depending on whom you ask and how much work you want - there are threads of people using surplus parts and going under 2k - however they replace every wire in the whole machine.
I’m working on a lathe centroid acorn style. It’s going to add up. Not $20k but a few thou in parts computer, boards, encoders, motor drivers, software....