[HH] 3D printing

[Jack Coats]

your numbers are not to far off for high volume production molds, but
there again is a DIY hobiest community
at work.  There are DIY machines from commercial sources, basically do
single shot of half ounce or less molds.
If you want to go hard cord DIY, look for the plastic molding books
from lindsaybks.com - and supposedly
they work OK but are not commercial quality.  Much of the technology
is similar to the reprap (temperature
controlled heater).

These hobby machines can be made for little if you have scrap and good
luck on eBay.