Lots of good points made about the car's value. It is only worth what someone is willing in to pay. There are lots of them out there, it's not a rare C3. Go look on ebay, always all kinds of C3's on there. So is the car really optioned out ? , is the color combo what you really want ? 7K , so the tires are probably original , and anything over 10 years old are not recommended to be safe. Do you want to drive this car or just look at it and show and shine once in awhile ? Distance and vehicle safety inspection to licence are in your favor here so that is worth something. Does she have all the car's history, bill of sale etc ? Windshield, exhaust system all original ?
2 years ago when I was looking for a C3 I turned down a mint 81 with 49K for 17,000 . I didn't like the colors and no power seat and mirrors. I ended up with a very nice loaded 82 with what I wanted for only 12,800 . So look around as they are out there. And if that car is what turns your crank then make her a offer , if she says no I think she will be sitting on it for a long time at 30K . I can point you to a new 78 Pace car in alberta, original owner, 34 miles ( bought in usa ) , think 40K will take it last I talked to him when I was looking for mine.