Hi
Internal order won't give you multi dimensional profitability..
If most of the costs are going to come through pricing procedure, then that means it will be posted at material level. So why do you need profitability at sales order level?
Imagine a car seller. He has to incur major expenses like music system, speakers, blue tooth, seat covers etc to sell the product. In this case, it makes sense to collect cogs and revenue at sales order level. If your case is like this, then collect at SO level.
You can hit the cogs as soon as you do GR against PO.
Br. Ajay M