When I looked on the sage site it went through and talked about item cost hierarchy -
In the Purchase Order Module only, the hierarchy begins with:
Vendor Price Levels
For Standard and Average cost items in Purchase Order Entry, Receipt of Goods Entry, Return of Goods Entry (no purchase order specified), Material Requisition Issue Entry (one-step) and material requisitions entered in Purchase Order Entry, the cost hierarchy specified below for Standard or Average valuation method is followed.
For LIFO/FIFO/Lot/Serial cost items,
Vendor Last Cost is used
If the Vendor Last Cost is zero, or no vendor is assigned to the item, then the Item Last Cost is used.
If the Item Last Cost is zero, then the cost hierarchy specified below for each valuation method is followed.
In the Auto Generate Orders Selection window, when selecting 'Update Unit Cost With':
Standard Default or Last Unit Cost - the Primary Vendor's last cost is used.
Standard Unit Cost - the item's standard cost is used.
Average Unit Cost - the item's average cost is used.
If any of the costs are zero for the above selections, the unit cost used follows the cost hierarchy based on the valuation methods listed below.
Standard Valuation - The standard cost from the Inventory master file is used. If the standard cost is zero, the unit cost defaults to the last cost. If the last cost is zero, the unit cost defaults to the warehouse average cost. If the warehouse average cost is zero, the unit cost defaults to the item average cost.
Average Valuation - The warehouse average cost from the Inventory master file is used. If the warehouse average cost is zero, the unit cost defaults to the item average cost. If the item average cost is zero, the unit cost defaults to the last cost. If the last cost is zero, the unit cost defaults to the standard cost.