has anyone brought the standard cost of the item on the purchase order? the scenario is they want to ensure the standard cost is created before the purchase order is placed/created.

I would assume you can link the data from the item record onto a transaction column on the purchase order. you can probably also script some client side logic on page init to validate that the item is costed correctly, if that functionality is not natively done

On transaction column i don't see the standard cost field to map, it is on the location sublist, so it's on the item record under Purchase/ Inventory > Location > standard cost