Agree with Randy on the $300-500 USD range, maybe a little more if that scuff is bad. If you're planning on keeping the car a while, have the bumper removed. Painting it on the car doesn't get the paint into the nooks and crannies properly and it will eventually start peeling from there.

Get some body filler and do it yourself. If you don't like the results, then take it to the body shop. Nothing to lose.