The Line Item Detail - Cost field displays the Average Cost from the item's Inventory database record at the time the item was saved with the Sales Transaction.
The Average Cost for each item placed on a Sales Transaction is saved with the transaction Line Item Details and is used to calculate profits on reports.
Editing the Cost on the Line Item Detail screen changes the Cost for the current line item only. It also changes the Percent Profit to the right of the Cost field. The Price field is not adjusted. It does not change the Average Cost field in the item's Inventory database record.
To edit an item's cost, select the desired line item on the Sales Transaction Item Entry screen and press [F3] to display the Line Item Detail screen. Navigate to the Cost field and edit as needed.
See:
Line Item Detail Screen Contents
Sales Manager Contents