Add a column in which we can put amount and it should be added to the price of individual item.

I have a car service workshop. Whenever I make a bill, I add multiple parts and then i have to add labour charge as service individually for every part.

Example :

As you can see S.No. 2, 4, 6 are the individual labours charges or parts fitted. It will be highly useful if we can add a column and its amount will be added in each parts.