All ten of those cars are crap to begin with - I just picked up a 2000 Buick Park Avenue Ultra with 67K original miles and nary a scratch on it for 6 grand. Original sticker price 38K, it has the excellent V6 with a factory supercharger. Gets 25mpg on a cruise with a ton of passing power.
My 1998 Buick Park Avenue Non-Ultra has 190,000 miles and plenty of scratches. Plenty of nuisance problems (stuck doors, windows , bas head lamp lenses) and I HATE daytime running lights, but that 3800 drivetain is a champ.
Those Park Avenues are sleepers. Nobody thinks twice about them and you got a bargain. Great car.