Well, my mom got a call from my aunt down in Florida today and was asked about whether $5,000 for a 1990 Jaguar XJ6 w/ 91,000 miles was a fair price (They claim that it's in excellent condition and garage kept, since they visited the lady at her house yesterday). I told them that the price was a bit too steep, and after KBB'ing it, I was right. The appropriate private seller retail is about $3,000 => $3,850, depending on the trim level/special editions.
Now, going away from the price (which I've determined is $1,000 => $1,500 too high), is the Jaguar XJ6 from the early 90's reliable? I've heard pros and cons for the 6, but I know the 12's infamous for it's horrible reliability and poor efficiency.