Your FINISH SHIPMENT button is orange, preventing you from completing your shipment because one or more of the items in the shipment is missing a PRICE.  If you locate the item(s) and double click the empty PRICE field, the PRICE dialog box will appear in which you can enter a PRICE for the item. Once all of the items in the shipment have a PRICE the FINISH SHIPMENT button will turn blue and you can click it to complete your shipment.