Well, I am trying a kit- forget what they call my version. It was 300 bucks. Construction went reasonably well aided by a forum, but now I am trying to interface it to computer and get it calibrated. That is harder than building it.
And, I have been trying to learn 3D software. It is sure a lot harder than 2D, which I feel fairly adept with. One problem is that you need a pretty decent 3D CAD package, and the cheaper ones don't really do 3D CAD all that well unless your parts are mere extrusions or tapered extrusions.