I think if that were the case, it would read approximately, and...

I think if that were the case, it would read approximately, and no requirement for milestone payments.
Milestone payments would be on the basis that certain objectives were being met in relation to manufacturing.

I would expect it would be along the lines of
Seller - I will sell this to you for $10, and you will produce this for us, at a cost of $1 per widget, and we are prioritised through the floor.
Buyer - Ok, I will pay $4 up front, and everytime you product 100 widgets, I will rebate you $1 to a total of $6, making the total $10.

Buying and selling production facilities, with manufacturing contracts in place, is slightly different to residential and small commercial.

I am sure we will find out over time, but this is my take, hence no concern, as it is quite typical how the boys play.
Albiet, in this instance, it appears it was LC who was overseas finalising this deal.