Virtual products and price calculations

I’m using dolibarr 9.0.3 and enabled the kits (virtual products) This works so far and I can setup a structure of products which consist of other products. In this case there are some PCB modules which is a union of different parts. The PCB itself is not manufactured ourself but purchased from. Then there are some metal enclosures for the board which we do manufacture. At this point there is a problem. I added a product for the enclosure but the price calculation is based on buying price. There is no buying price because we manufacture the enclosure ourself. How do I manage to consider a the price for this. Should I add the material buying price and services? What is your reccomended workflow for this?

Please can you help Explain me How to “I can setup a structure of products which consist of other products” I am using 11.02