I mean, at the end of the day, we're talking stepper motors, switches, a resistive heater, (EDIT: or two. Forgot about the heated bed) a thermistor (or two, heated bed again), a few fans. maybe a solenoid. What you're usually buying with a 3d printer is the *hardware* and the mechanical engineering that went into it, The on board software is... sufficient, but there's a reason things like Octoprint and Klipper are so popular.