Yes it is very likely that you have a leak, but if the car has NEVER been recharged, the possibility exists that it just leaked out over time. A one ounce per year leak would have leaked enough to render the system inoperative.
$165 sounds a little high, but if they are the only ones that will do it in your area, that probably explains a lot.
The main thing is that you are dilligent in looking for leaks, you don't want to do this again soon. It would be very good if they put in some UV dye so that if there is a leak then it will be easy to find.