So we Invoice as eg Iphone 5s Screen Replacement.
in the bundle we have the screen as a item.

it needs to be hidden . but i want to ability to add how many were used -
so the cost goes against the job so we know if it was a lost.....

its a little confusing. i know we can alter the bundle when creating it -
but generally we just want to sell the job as the line item on the invoice
- but have the cost and inventory item in there too like a hidden line item.

perhaps instead of using the bundle the way we do we could introduce hidden
items on invoice