For a Prusa, the cost is less the an original Mendel
Metal parts, nuts, bolts, screws (A.K.A. Vitamins) $45ish
Printed Plastic Parts $100
RAMPS Electronics build it yourself $40
4 Pololu Carriers $48
Arduino MEGA Clone $35
PC Power Supply $50
Stepper Motors $20-$50 depends
Miscellaneous parts (Hot End, Bearings, Belts, Thermistors, Wire Connectors) $100
You are looking at a price somewhere between $350 (good luck) and $450.
As for speed??? That depends on how well you build the machine.
Cost of plastic is about $65/5 lbs on average
