All depends on the value of the rod, as you say. Many employers that use courier services will allow employees to get parcels sent at company rates which is usually a lot cheaper, or at the very least, get friendly with your dispatch manager and they might let you!!
Best packaging is as robust a tube as you can find (without getting too heavy) cut to about 6 inches longer thasn the rod, wrap both ends in buble wrap so that the ends just fit in the tube and the wrap extends 3 inches or so beyond the ends of the rod. Also do the middle for long rods. This will keep the rod firmly in place in the tube. Don't forget to tape on the end caps of the tube - I know someone who forgot and his rod came out and was demolished!