Kris. . .
If that car she has is what I understand it to be, it was worth the price of a C5 + 40 grand for the customization. Therefore at 20k you could probably go and turn a profit on it after driving it a couple years. You always hear stories about things like little old ladies with their dead husband's 3000 mile challenger sitting in the garage that's worth 100k and they're trying to sell it to the neighbor kid for 5 grand. . . I think you might have one of those situations at your disposal, and if I had 20 grand and knew where she lived I'd be giving you different advice and taking it for myself
I'd do more research though, I couldn't find much info on those cars and they may have had their info switched up with those 789s.