It is hard to tell from the picture if the tubing behind the fins is damaged. The damage to the fins are not a big deal.

Did the tech do any investigation of the leak?

Are planning to be in this house a long time? It may not be worth spending the money to repair a 14 year old Arcoaire AC. Are you sure it is rated at 12 SEER? More likely it is about 10 SEER.

Thanks for the response. I don't know if the close up provides any more information on the tubing -- I can't see much beyond the fins (link here and also attached).
https://dl.dropboxusercontent.com/u/6994270/P1040528.JPG

I think the tech just assumed that the damage included the tubing since the system was flat (no refrigerant pressure). I didn't see him do any additional investigation.

The original purchase paperwork lists it as 12 seer; I don't know much beyond that.

Thanks again for the response.

Looks deep enough to have hit tubing.

If you want to be sure have it pressurized with nitrogen.

You will quickly find out if it is leaking.

Thanks for the idea!