Oo... ouch. I had to have my bumper repaired recently. It was covered by insurance, because the incident was not my fault.

The damage on my car was probably worse than your dent-- there was a small hole and the whole plastic cover was out of place. The original quote from the body shop was for about $500, and that was for repairing a small hole in the plastic and repainting-- it only covered what they could actually SEE. When they got inside, they had to replace some things underneith the plasic, so the total was more in the $700 to $800 range. I'm not sure all the bits they had to replace, but they talked to me about the possibility that several things could have been damaged: the styrofoam, the clips, etc.

I was looking online at Honda's part store (you can access that from Ownerlink-- go in like you're going to buy accessories and then click the "Parts" link) and they have bumper parts and a nice little diagram of everything that is underneith it. I'd link to that here, but it was through my ownerlink page (password protected), so I don't think it would transfer over... but try Honda's website if you're interested.

Good luck!
--A