Are they hard to find?
The Audi V8 Quattro has been out of production for almost 25 years (1988-1993) and not a lot of them were built. There are still some out there, but a lot of them are in rough shape. I see two or three of them each year on Craigslist typically for around $2500. Ones fitted with manual transmissions are extremely rare.
The newer A8s are much more common and easy to find.
Hi you have not said which model yes a Q8 is a V8 bit so is the Q7.
Depend on year and mileage...
not at all the price depends on mileage and condition