CAD is a generic term for Computer Aided Design. If you think of AutoCAD, yes, it is rather for 2D drawings. I used to be working on SolidWorks, which is a 3D CAD program, specialised for mechanical engineering, but also ship hulls and frames can be designed in it. But it is unsuitable for sculptures.
A year ago or so I was making inquiries about scanning and editing figure heads (the master would have been manually carved and scanned in). They quoted 1 week editing time for a figure head using the point cloud from the scan. This resulted in a $10.000 cost for one edition only, not including the toolpath. I think things have changed since but they should still be on the expensive side. It might be economical for a series production but definitely not a one-off run (this would defeat the purpose anyhow)
Yes, time will change everything. The software we used to use was pirated, but then things changed. As far as I am using rhino, its price in China is only $400, which is acceptable to us. Now rhino is used in many design fields
When I first learned 3D animation, I had contact with cloud point scanning, which is based on the principle of manually marking coordinates on clay sculpture.
Now technology is developing too fast. Many high-tech things may be popularized in another 3-5 years