Question about ship research costs

[Revenge1916]

On the Aoba when you look at it in the tech tree it says 33,000 to research but when you click on it and bring it up on the screen it says the research cost is 40,000 why is this different?

[Noshiro_]

The number on the tech tree doesn't account for the hull leading to the ship, but clicking on it does.

[Legendary_Typo]

You need to research all prerequisites.

[Revenge1916]

ahhhhh ok that makes sense, thanks guys