Intercompany Invoice

Can some one help me to resolve following case:

In my scenario of intercompany invoicing process header branch plant is having dynamic price which is driven from interface. There is always fixed margin for header business unit that means transfer price between detailed business unit and header business unit is selling price - header business units margin.

In standard JDE we can hace transfer price as cost+markup or price. in this case how can we resolve the transfer price to be calculated based up on selling price.

example

Sellers margin is 10

if selling price is 100 then transfer price between header business unit and detailed business unit is (100 - 10 =90). If selling price is 105 then transfer price is 105-10 = 95.