Very nice work..Charlie, hopefully not completely dissuaded. I find the process of doing CNC patterns and integrating them into my projects a ton of fun. But it will depend on what your expectations are and the willingness to spend time on the software and hardware. A hobby machine is a hobby machine. I have a ~2K hobby machine made mostly of plastic. I do not expect it to run like a 10K or 5K machine but at the end of the day it provides me with the 3d (2.5d actually) carved piece that I programmed into the machine. Early on I used other peoples patterns but now I make all my patterns from scratch.
It taken me about 6 years to get at this stage of pattern making and I will call myself an advanced beginner. It is not easy making 3d objects from 2d images most times (sometimes you do get lucky).
I use Blender 3d (free) and Zbrush (not free) to make my 3d models and then export as STL to my cnc software to create the patterns. I also use grey scale depth map images sometimes for different reasons. Not all 3d models make good cnc patterns. The learning curve is steep but not insurmountable since I am an example a monkey can learn with enough time.