Don't want to put you off but what you after doing just can't be done reliably by these cheap nasty things. To cut inlays with fine details will mean you are using tiny cutters and these snap for fun on even sturdy machines with spindles that have very little to no runout and lots of power.

If you just want to learn the principles of using a CNC machine and cut a bit of balsa wood etc, then go for it. But don't try putting any expensive hardwood materials or guitar necks near these things that you don't mind scrapping.
You'll get very frustrated quickly if you buy this with the intent of doing any meaningful work with it.