That is a good question. The main challenges are in the design of the ships. This applies to any long-term purchase. When you are buying something that has not yet been built, that does not yet exist, the costs come with a number of risks. Essentially, there is no basis for comparison.
The specifications are also unique to each country, particularly those pertaining to warships. The time horizon is also very significant. The ships we are buying do not presently exist. This is not like buying a car. We are buying 15 copies of a ship that will take several decades to build. Inflation is a major factor, especially when we are talking about 25 or 30 years, or even longer. These are the main risk factors that must be considered when costs have to be determined.
If we have more time, I am sure that Ms. Malanik and Mr. Penney could handle that question a lot better and much more clearly than I can.