Originally Posted by
ger21
You won't be able to get a "good" machine with a low budget, but for learning purposes, a cheap chinese machine from Ebay will work.
LinuxCNC is the only Linux control software available. You may need to swap some electronics to use LinuxCNC, as most chinese machines are setup to run Mach3.
I'm not familiar with any CAD or CAM software that runs on Linux, as I'm not a Linux user.
You can do a lot of learning without even having a machine.
You can learn CAD and CAM without a machine, and run control software in demo mode to see your code running.
I actually think it's better to learn as much as possible before getting a machine.