On the face of it CIG increase prices on ships when they either start work or invest further development time into ships.
Price rises really shouldnt matter as if you are initially interested in a ship and have no money, pick up the absolute cheapest ccu you can afford at concept and sit on it till you are sure you want the ship.
If its a capital ship and you cant afford it, then chances are you will never be able to afford it so dont go down that route for the sake of your own personal well being.
My personal point of view is most prices are simply because they can, very few of them are justified.