Auto body repair & detailing: Help! Rear bumper damage question..., fender bender, horizontal lines

Question
Hi there.  I recently got into a fender bender; I was driving about 5 miles an hour or less, and I bumped into the car in front of me.  Both of us pulled over to assess the damage, and there was none to my car, but a little bit of what looked like paint crumpling to the lady's car that I bumped.  Nothing chipped at all; the paint just got some horizontal lines in it.  She has sent me an estimate for $615 which includes replacement of the bumper cover, refinishing it, sheet metal labor and refinishing labor.  I guess my question is, what does all this mean? Is she getting an entirely new bumper?  Is all this necessary for the damage I perceived?  And is this estimate reasonable?  I am just shocked to receive such a high estimate.  Also, when is a whole new bumper necessary? Any information you can give me, or questions I should ask/suggestions would be very much appreciated!

Answer
Lauren it shouldn't be replaced it can be repaired,but some times when its not your fault and some one hits you then you like new parts not for the old parts to be fixed.to repair it you shouldn't spend more then $350 and to replace it that price sounds fair.but i would make sure you tell the body shop you want the old bumper when they are finished b/c some times they charge for a new one and fix the old one.