Speakers for Linn Classik? Budget $400-500

A friend is interested in buyign a Linn Classik, and has a budget of about $400-500 for speakers. She would prefer to buy used. I think Linn Tukans would be ideal, but they rarely show up used. Can anyone recommend some decent monitors in this price range that show up used with some frequency? I am thinking B&W, but really don't know anything about them.

Thanks.