Audi 4000s not shifting

[Chiwen]

I have the opertunity to buy an 1983 Audi 4000s and have a few questions. For some reason or another the car is not shifting. It's an Automatic. The speedometer does not work also. Other than that its mint. Clean, no rust or body damage. Does anyone have any ideas on why this car will not shift? What can it be? How do I fix it, and how much will it cost? I can get the car for 500 bucks, so I do want it. Any help?

Thanks in advance.