"When would you start using a 3D Printer?"
The results of the poll clearly indicate that most users would start using a 3D printer "when the cost drops below $1,000 for a machine". A few indicated they would go for a $3,000 or even a $5,000 machine, but that simply suggests where the "bell curve" of affordability exists.
Interestingly, the least expensive commercial 3D printer today is DesktopFactory's 125ci 3D Printer, which is priced at $4,995 - just barely below the highest affordability threshold of the poll. Perhaps we should wait for the DesktopFactory "225ci"?