If you are lucky, you could find a bumper cover from a junkyard that matches your color. Even if you had to have it shipped, that saves you the cost of painting and some cost on the parts (and the vent thing should be included with it).
I broke a rear windshield on an Acura Integra. The windshield glass replacement was $700, but I found a junk yard that sold me the entire rear deck lid in the same color for (IMS) $150 - which was also an easier install.
Paint costs vary a lot in price and quality. I have a faded area on my trunk (clear coat fading, and I've been quoted from $200 to $700 for the same repair.)
You might or might not need to replace or repair some of the supports behind it - depends how hard you hit whatever it was.
Last edited by Tiger-Heli; 02-07-2014 at 04:40 PM.