Authorities on both sides of the border in the Twin Ports are looking for a 24-year-old Duluth man who shot another man when they argued over the sale of a vehicle.  Police say Edward Isaiah Austin is considered to be armed and dangerous.  He is suspected of shooting the 29-year-old Superior man in the head, although the victim didn’t realize he’d been shot.  The shooting happened during an argument over a 400-dollar transaction.  The victim’s name hasn’t been released.  He survived, telling police he felt okay, but had a headache.  He thought Austin had hit him in the head.