The seats used in the V8 are interchangeable with the Audi 5000 (84-88) , the Audi 100/200 (89-91), the "C4" Audi 100 and S4 (92-94) and the first-generation A6/S6 (95-97). I guess that you live in the US, so you would have standard power seats on all models.

The cheapest solution would surely be to purchase a good set of used seats. There are some places in the US who specialize in selling parts for the V8 online. Jeremy has some linked on his website (look at his sig).
Most "worn out" leather seats can be treated to look like new by recoloring and regenerating them. For this, best contact a reputable local auto detailing shop. This also should be a lot cheaper than buying new patterns plus having them installed.
If you need new seat cushions, you have to go to Audi. These are also not very expensive and well worth the expense, especially with worn out sport seat side bolsters.