Approximately how much should it cost to repair front end damage?

The car was involved in a front end collision where it crashed into a pole in a parking lot. The front bumper was torn off and was not recovered by the towing company. The radiator was dented in a concave 'V' shape. There was a metal bar in front of the radiator that was also bent. An auto body shop gave me an estimate of around $4500 to fix the damage. I was wondering if this was a good estimate or if I am being ripped off. I was told that most of the cost would come from labor and that's why it was over $4000. The car still starts, drives, and runs. I only had liability insurance so any repairs will be out of pocket. The repair guy acted like he was interested in making an offer for the Acura as-is, what would be a decent amount to accept for it?

Thanks in advance