[A] While doing Physical Stock Reconciliation (PSR), you have the option to fill "Transfer Price" in the excel sheet.
[B] It is recommended that you fill this field because the value filled here is updated as the in or out price of that item in the Inventory.
[C] You can either give the price that is already saved in the inventory. You can also give a new price if you wish to update the older one. If no price is mentioned in the inventory, you can give the latest price that you want.
[D] If the price is not available at you then you can add 0 in this field, but this will may cause error while checking BOM cost if you check costing.
Keywords: what to fill in transfer price, can I leave the transfer price blank