add amount to shipping cost per product
You're probably wanting the basic solution explained in this video: https://commerceguys.com/blog/using-calculation-rules-add-item-shipping-commerce-shipping-screencast

With a little modification, it looks like this:


Add a new "Calculation rule" for your shipping service.
Add an action loop that loops through the line items in the order.
Add an action "Calculate a value" and multiply the quantity times a field which holds the shipping price you want to charge for that item and store it in a named variable.
Add an action "Add an amount to the unit price" that adds the named variable to the unit price of the shipping line item.