Mike brought up a key point earlier in this post, the pricing. And then, you have to understand what you get with the lower priced options.
I downloaded the demo version of Cut-2D from Vectric. It was inexpensive at $150. Using the demo I found it had a lot of good features, but you were restricted in that package to closed vectors. What that means is if you want to CNC a series of unconnected lines, it is not possible unless you make them extremely small rectangles. Think about making a ruler with lines every certain distance, you would have to make each line a rectangle and slightly wider than your cutting tool.
V-Carve Pro is well respected for 2-D signs at $600, while the best CAD/CAM at Vectic is Aspire for $2,000. If you read the Aspire information it dwells on 3D relief from 2D sketches. The gallery of pictures only show signs and carvings. There is no information on if you wanted to actually design a mechanism with interfacing parts.
I would love to have V-Carve or Aspire, but I don't do what they are best at. It wouldn't make money sense for me. To really do those carvings you need a CNC with spindle and very high movement rate. Read a bit on how many hours some of the 3-D carvings take to cut.