Manufacturing Path/Estimating Production Costs for Arduino-Based Project

Wow! 10K, 100K unit production. I'd say you guys should invest in some
"professional" level help. You certainly must have the money up front if you're
talking those sorts of production levels. A good professional could easily
cook up the figures for you for $1000 or so. Money well spent. There is an
immense amount of risk in a product with those production levels.