What's the material cost? And the printing time?
I looked into 3D printers about a year ago. At the time a printer that was barely sufficient from a resolution standpoint (think of it as a three-dimensional pixels) so you end up having to sand and finish pieces, but okay . . . It was going to be about 2200-2800$ when set up. More expensive ones, particularly those that worked in sintered metal instead of plastic, were much, much more, ($30K) but this made stuff out of a type of plastic.
Anyway, the material it "printed" with was a type of plastic that came in feed stock reels that looked like the bulk stuff you buy for, say weedeater line, sort of like heavy fishing line maybe, that ityou loaded and the printer took what it needed as it fed in as it needed it.. The cost per reel was not that great -- can't remember the details but because I don't I'm certain it was not outstanding. But the amount of material on a reel was not that great, so if you needed a lot of material, it could get costly. Printer time was slow. I think it could take thirty minutes or more to print out, say, a small model car (1:43 or so).
Anyway, I remember calculating the cost to make, say, an entire 1:43 car kit - body, interior, tires, to paint and assemble. ( I did not have the data file for one but I figured in time they'd be available . . .). It was reasonable, about $20 or so. Not cheap but competitive. The cost to make a whole building, though - like suppose you wanted to "print out" a duplicate of an Ameritown kit, would be about $180 - $200. This really didn't matter anyway since the model I was looking at could not print anything as long as a three-story Ameritown building side. It could only do things about as big as a can of Campbells soup.
One thing: be careful about options you have to have with the printer. The one I was looking at was advertised only $1600 or so until you considered everything needed: the power supply, etc. Nearly doubled the price. One required option on the model I was looking at was an add-on that would allow you to change reels of feed stock in the middle of printing - say the thing you were making required more material than the reel had left (I think this would happen often). You needed the option (it was some sort of additional part you added as well as some more software) so that you could pause, remove the old reel when exhausted, feed in another, and take up where you left off printing.
I am not the least bit negative about 3D printers. Excited aobut getting one eventually, but I want to both let the technology mature and stabilize a bit, and learn more (are there different file formats, as there are for pictures and diagrams now, that are best for different aplications depending on what you are making? Are there aftermarket suppliers of the feed stock reels? for this reason I really appreciate when people like SandySimon take the plunge and tell us about it.
