Last buy price vs FIFO cost price

On the system, each product has two cost prices:

1. Last buy price: this is the last purchased cost price. It can be changed at any time (from the SKU variations entry page or via data import). It is used only for suggesting the purchase order price for new purchase orders (given that there is no supplier price list setup). After a PO has been receipted and costed, the system automatically updates the last buy price to the PO price (against the PO location).
2. Product's cost price, FIFO cost or total weighted average cost: this is system calculated and driven. It is for items that have already been receipted and landed costed. When the last buy price is changed, it will not affect this cost. After a purchase order (or inventory adjustment) is receipted and costed, this cost price is then re-evaluated and updated. All sales reports COGS including the price tier export data uses this cost. It is the actual stock landed cost.