Well, you did say that you were thinking of starting a
business, so I assumed that productivity is a bit of a concern. Prototyping is slow enough going, with good equipment.
Typical homebuilt takes quite a lot of time to do correctly, although I'm sure you guys could design something.
It can be frustrating to find out that you've built it "short" of all the features you will need, and that is why a commercially made machine is a good choice: someone else has killed most of the bugs off already.
What kind of accuracy requirements will your work have?