I will second the recommendation for Fusion 360. The personal edition (free) is already very capable and the commercial version fits in your budget. It covers both CAD and CAM in an integrated solution. It runs natively on macOS.
However you might want to start with Carbide Create (free version), which also has a native mac version. It is very limited (2D paths only) but it may be more approachable for the first operations such as surfacing your wasteboard, learning about cutting speed, etc.
Carbide sets very conservative cutting speeds. You can overwrite those but I found it helpful when I was starting (more chance to stop the machine in case of error). Switching to Fusion and his more aggressive paths was… frightening initially 
Also the CAD section is really just a (very simple) drawing tool. More limited but more approachable for the first few days.
Another thread to consider: