Or they'll switch to producing the "ink" for the printers, as that's also a pretty non-trivial business from what I've understood (and will even be more so when

Or they'll switch to producing the "ink" for the printers, as that's also a pretty non-trivial business from what I've understood (and will even be more so when 3d printers can print more advanced objects). 3d printing will be a win for convenience and personalization, but not for cost, certainly not if you want to produce zillions of equal objects.