now to answer your question about how much parts cost, motors, treads, arduinos, look those parts are cheap, hundreds max, depends on how big, accuracy of the print, stability of the frame, etc etc, better quality, stronger box, more $$, the expensive parts are probably the printer head, because that's the sophisticated part where if you want quality you gotta pay, all the other parts you can make with pluming parts, and most of the codes and software are opensourced, otherwise you might have to pay a premium for all in one packaged software which is not the best idea since they were designed for a specific system where they sell with the printer so... look its cheap enough these to buy an dual extrusion head for abs/pla/other regular plastics, for 300-500$ don't bother making one yourself, unless you want a nice education on how to build a 3d printer from teh ground up