How much is a good price for a Volkswagen bus model T2b?

Im looking into buying a volkswagen bus type t2b
The one im looking at is in perfect condition on the outside
the inside has the front two seats in good condition
and he said it drives good and hasnt had any major problems as long as hes had it
no back seats but thats actually good for me
i dont know the exact year or mileage yet, but im finding it out soon
I do know that this model was made from 1972 - 1980
and it has an awesome paint job

The guy im trying to buy it from is asking 5500
but im going to try and haggle him down
whats a fair price for this car?