Basic math tells you iPhone X will be very supply constrained at launch.
Even the journalists who went to Steve Jobs Theater mentioned there were far too few demo units on hand.
At 10k/day, even if Foxconn increased production by 25% every 7 days, Apple only ends up with 1 million units on October 31. If we pretend Foxconn were assembling 10k/day since August 2017, that only adds 300k units to the pool.
During previous launches like iPhone 6S, Apple sold 13 million over the launch weekend. Traditionally, 40% of those sales are the expensive Plus models, which translates to 5 million units.
Apple will have at best 1.5 million units of iPhone X at launch for worldwide consumption.