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Well that could be true if you are a casual user of 3D Printer, but if you really want to put your machine to produce it is expensive. Yes you can need a shreding machine and this Filament extruder and work in calibrate and got a consistente filamente, but when you got it, you can low your budget to 5Euro/Kg (pellets) or 0Euro/Kg (Recycle). But the best thing is the green. By the way you dont need make the filament Extruder. The Italian guys who made the Felfil Evo sell it in 500Euro or 280 Euro for basic parts and you put the electronics (arduino basic), there is another kits too. So I think many people can got great savings for this.
Not it is not enought, however you can look a geared stepper and check the Torque, you will need gears reduction because torque is big.