Hi Tapera,
If understood correctly your issue, I feel this small costs can be captured operation-wiise also in an Order by using the Quantity and Value fileds given in the Enhancements tab of Operation Tab-Page of the Order.
See this: (This is a screen you get when you select an operation and click on the Enhancements pushbutton at the bottom.
You see 2 fields for each (Quantity or Value).
1st one is for Numeric entry and the second one is for Unit.
You can view the F1 help of these fields.
Hope this information is of some help.
Jogeswara Rao K