a/c leak in "coil"?

[atl]

My a/c went out so I took it to a place to test it and sure enough there is a leak. The place doesn't do a test for where the leak is, but a ton of freon was leaking out (it looked like smoke) and the dude looke at the bottom of the radiator and saw some oil, and from where the "smoke" seemed to be coming from said "it looks like a leak in the coil". He said a place down the road will install a new one for $360. So my questions are,

1. what is this "coil"?
2. where can I get one and are they easy to change out?
3. is $360 fair? (if I go that route)

Thanks for your help.

 

[Glacier991]

The "coil" is called a condensor. A new one will run $150 to $200 for the part. Replacement is easy. The system will then need to be evacuated and recharged in order to function thereafter. If the $360 includes all of that, it's in the ballpark.