Conductive ink printer could be an interesting thing at a low price (if the technology is useful, prices might come down eventually).
Still, it mentions:
~5 USD
Board cost.
I'm not sure how this compares with the cheapest Chinese fab house (for those that can wait up to a few weeks), but I understand that even more expensive - but rapid - could be worth a lot for some people in some cases. I don't even know much much the current home etching methods cost per board.
I am not sure how the process is better than "home etching" from an ease-of-use or productivity perspective.
Home etching costs peanuts, but you do have to make the effort to get your process to work, and expect plenty of failures to get to that process, just make sure you document what works, and possibly more importantly what doesn't. Keeping to the same recipe is an extraordinarily good idea. Using different stock, in particular changing you pre-sensitised boards, or chemical mix/dilution, is not a good idea. I do my own etching sporadically, I can go weeks without needing to do a quick board then suddenly I might do a dozen in a couple of days, but it took quite some weeks if not months to get my process to work.
For the avoidance of doubt, my process very closely follows Mike's (
http://www.electricstuff.co.uk/pcbs.html), but I "discovered" it without prior knowledge, I just did self-learning. What is nonsense and a waste of money for kitchen table etching are bubble tanks. Use your eyes and learn, bubble tanks will just get in the way. Plastic take-away containers are designed for the purpose ;-)
As a tool, what is very useful for any prototyping is a decent PCB guillotine, and while they're not cheap, my they're handy, way more useful than any bubble tank.