It's a pretty complex piece of hardware, there are so many variables to get a piece right. Material, spindle speed, motor speed, drill bits, not to mention that you need to be proficient with at least 3 kind of software (CAD, CAM and the actual CNC control software).
It is also a very expensive "hobby", the cnc machine is probably the least of your worries. Good drill bits are expensive and they don't last forever, sometimes you can sharp them and reuse but it depends on type and size. I bought a 2mm drill bit that was alone $30. Then you have cutting oil, grease, clamps, and of course the raw material and since it's hard to make it right at first try, you are going to have a lot a wasted material. Not to mention the cost of the software that goes from free to $5k and more.
That being said... when after 1 hour of setup you finally see this...
... all your efforts are repaid: 24mm sharp! This piece is actually a commission work for a guy here on the forum.
The other side is off by 0.0-something
But for being my very first experiment with acrylic I'm extremely satisfied. I know it may look something really simple... but I have to start from somewhere
and I hope you can see the potentiality 
This weekend I hope to be able to work on a poker wooden case, then I'll start working with aluminum. A new world of custom keyboards is opening up
If you have any question or have any suggestion, please hit the reply button
