I totally agree with you, but I’ll mention a counter-argument that came to mind…
When printers (the old-fashioned kind) were first affordable enough to put in homes as well as businesses, and especially when they developed the ability to be photocopiers too, there were many articles detailing the cost-per-page for printing and photocopying which concluded that for most people who did not actually work from home, it was cheaper to just go to Kinko’s (e.g.) for those times one might need copies. I was one of those people who looked at the numbers and determined for myself that the time and energy savings of not having to go to a copy shop every time I needed a copy, plus the convenience factor of instantaneous copying (even at 3am on a Sunday, back when copy shops weren’t 24/7…not that it’s a likely scenario in my personal experience) made the slightly higher per copy cost totally acceptable.
My guess is that we’ll see the same weighing-of-the-options for 3D printers too. Convenience is a major factor, often more so than bottom-line price. Inventory of raw material is the big drawback…pounds of plastic take up a lot more space then a ream of paper and replacement ink cartridges.
