Very cheap ways of doing it would be:
Sand it down, so it's not raised at any point, then get some vinyl the exact same color as your bumper. You can get this from a sign making shop. Apply the vinyl (same stuff as decals) over the top. Once waxed a few times you'll never notice it
Or.. Do what i do with my rear scratches from mis-judging bumpers in multi-storey car parks, just add a decal or two or four
Alternatively if your going to do it the right way. It will need to be plastic welded. I can get it done here for approx £25. You being in the land of custom garages i'd of thought a little hunting and you'd be able to match that price but in Dollars
Buying a new bumper, plus the respray and fitting would run into a small fortune
