Wrecked Chevy Cruze 2015

I recently hit the back of a Chevy
Cruze in my work parking lot. I was
going maybe 5-10 mph. It put a small
dent in the bumper and a small dent
in the bottom of the trunk under the
license plate. The kid took the car for
a estimate and called me about a
week later and said the estimate was
around $1600. I was a little shocked
but then to my surprise another week
later he calls me again and says they
found more damage after they started
working on it and the estimate was
now at $3400. I was in total disbelief.
Can anyone tell me if that sounds
legitimate or not. I can’t possibly
understand how it could be that
much to fix. Thank you