Maybe even more fun is to build one yourself. They are a great introduction to CNC hardware without some of the added mechanical complexity involved with something like a router or mill. The parts are fairly cheap because they don't have to be super rigid and the steppers don't need a lot of torque, plus there is quality open source software to run them on cheap microcontrollers (grbl on Arduino + a cheap motor shield from China). There's tons of videos on YouTube of how to build one from scrap DVD drives for instance, e.g. https://www.youtube.com/watch?v=0PmR_1dx77s