Selling price can be recalculated only from approved purchase orders.
To create a price list for the purchase order and recalculate new selling price for the items on the purchase order, click on the Create price list option in the menu in the purchase details page. 
This will create a new price list document.
- You can edit the price list and set a new price for each product in the products table.
- Click on [SAVE] button or press F9 keyboard key to save the changes, or click on the [CANCEL] button to ignore the changes and reload the price list information.