New condition price in PO value

Hi experts,

I've created a new condition type for PO. It is Freight (Value) with Fixed Amount.

My problem is let say I buy a material for a total of USD1000.00

Then I include the condition type into the PO condition for USD50.00

Under Condition tab, the actual price is USD1050.00

But the total PO value is still USD1000.00

What I wish to do is the total PO value will become USD1050.00 instead of USD1000.00

May I know how can I achieve that?

Thanks and regards,

JT