The Material Unit Cost panel shows the unit cost (cost per mass) of the selected material composition/stock. By default, aPriori uses the unit cost value that is specified in the VPE for that material composition/stock. However, if this value does not reflect the value that will actually be in effect for this part (for example, if material prices have changed significantly since the VPE last was updated), you can override the value used for the current part.

Click the Override radio button in the Material Unit Cost panel, and enter the new material unit cost (take care to note the units)

Click the VPE Material Unit Cost radio button