Yes they can be very expensive. We are (slowly) working on changing that. I would guess that within 10 years 3D printers will be in as many homes as regular printers are now. When I first started with this company 4 years ago our lowest priced printer was around $70,000. This year we launched a printer that is less than $20,000. It is still not to the point where the average individual will buy one, but we are getting there.
Technology is amazing isn't it? I remember back in '96, I attended a conference in Chicago. There were many potential technological prototypes at that conference. One was a flat screen high resolution monitor, light weight, thin. They were being marketed for use in hospitals for tens of thousands of dollars, to look at x-rays and other medical tests.
And now 15 years later, most of us have flat screen monitors in our homes. (not the large heavy CRT monitors previously used) It has been marketed as a space saver, more convenient (lighter in weight), and .. more advantages.
I wonder how 3D printers will be marketed when the prices work for consumers? The only thing I can think of that is similar to the product of a 3D printer is a 'sculpture'.
Let's say you want a certain type of seashell and no way to get to the ocean to find one, if you find one. You could have one made with a 3D printer. (marketing--to homecrafters?)
Similarly, you go to your clay firing workshop and want a certain shape to make a present for your friend, you could design one on a 3D printer, it will be EXACT.(marketing--to homecrafters?)
Or as an artist wanting to create a 'sculpture', maybe this or that rock is too difficult or uncertain (due to natural fracturing) to chisel, soap too soft for that kind of detail, a 3D printer could provide both the detail needed and take out the uncertainty of natural materials and still provide the product required.(marketing--to artists?)
What else? Headstones for cemeteries, food for photography purposes, ...
A 3D printer object could be compared to a 2D photograph. A photograph is 'like' a painting, a 3D printer object is 'like' a sculpture.
It's facinating.
I'll be watching to see how the next 10 years brings about 3D printers to the general public.