BNR32, I have had this sort of repair done in Sydney. They can recoat the bar in a plastic finish that is actually heated onto the plastic after it has been plastic welded. The finish is as good as new and will not peel like paint will (and yes they can match the original black/grey colour)and the cost to do it is very reasonable. Nothing is impossible, you just need to know the right people.
The price for the lower lip is accurate as I've just bought one through nissan. The trick is to go to your local smash repairer and get them to order it in for you. They get a discount from nissan and you give them a case of crownies for there efforts. $830 for the lower lip is a bit overboard. I was quoted $560 to buy it over the counter, I think you should check again on that one.