[tangfj]

Yes you should be able to do this by creating a SELL rate offering and creating a rate on it that has a cost basis of "Buy-Shipment allocated cost amount". Then if you want to mark-up by 20% then just enter a percentage of 120%. You can then create an agent to update the rate on the sell side shipment every time the buy side rate changes or when the buy rate is invoiced (this may require creating a custom agent event for sell shipments). Good luck!