What is the cost of classes built from other classes?

I have a faction that costs 15 points, I created a level 1 class, costing 19 points, because I added a trait that costs 4 points. Then i create a second level class based on level 1 class, and add 25 new trait points to it. What is the final cost of this class? - 15 x 2 + 25 = 55 or - 15 x 2 + 4 (trait added on level 1 class) + 25 = 59 Second Question: If I do a level 3 class based on a level 2 class, it gets 3 attacks or 2 attacks (ignoring the attacks bonus that the level 2 class gets)?