> The main factor in weapon prices is development cost and manufacturingClose: the main factor in weapon costs is development. The main factor in prices depends on how many are manufactured, what sort of maintenance there will be (huge business), how much profit the defense contracting corporation wants to make, etc.
For example, now that the Patriot missile is already developed, each new one made and sold for millions will have a gross profit. If you can say "material prices increased (unsaid: "by 20%, etc") so we need to double the price", and the buyer is motivated (started a war and exhausted their previous supply), and also they are already locked into your ecosystem, then that is a win for you in even more ways.
If you are money-friends with the head of the military, and they are infamous for corruption, violating laws and regulations, not caring about the cost of things they spend government money on, and gifting government favors to their money-friends, then you are golden.