Hi Thierry888
There's one way I'd suggest exploring, if you haven't already, is setting up the freight cost and local charges as items as well, then create a new item set it as the finished product built from the original item + freight cost + local charges, the cost of the components will transfer into the cost of the the finished product.
Here are the detailed guide on building items and Auto-building items, please do test it out first to see if this method would suit your company file set up and reporting requirements. You can make a copy of your company file, rename it then use the copy to test it out with real data.