Dealers have them for $100.00 a set.
Try http://www.weathertech.com/

I'm turning my 2002 A4 in off lease next week.  I have a set of
official Audi rubber floor mats, black...good for winter weather.  You
probably want the carpet mats, but if you want mine they're yours.
Just email at rbkfour at yahoo and they're yours, just pay me for the
shipping.