How much should someone pay for a 1997 Audi a4 Quattro 1.9t automatic with 170,000 miles on it?

It has the sport cloth seats. Base model.

 

There are too many other variables that need to be taken into account. How is the body? ride quality? service history? These things and more are important when buying a used car. Post up some more details and someone can probably quote a price.

 

not much that's an old car with a lot of miles
Do searches on ebay.com, cars.com, autotrader.com for comparable cars to see what they are selling for