I'm not sure this is true. "Plastic piece of crap" is only what's possible with cheap hardware today. Much better additive manufacturing processes exist - for

I'm not sure this is true. "Plastic piece of crap" is only what's possible with cheap hardware today. Much better additive manufacturing processes exist - for a price, but price is going to keep on falling. And sure, if you want to build ten thousand wrenches a day, casting is obviously always going to be much cheaper than laser sintering. But, particularly considering the derivative of current technology, it is far from clear to me that, if I need 1000 different parts, a 1/100th share in the laser sintering printer at my local hackerspace is going to be pricier than a 1/10000000th share in 1000 foundries.