91 audi 100 what is it worth?

I have to sell my Audi 100, it has leather, power, everything works, except
the fresh air vent, (it is either the spring or the vacuum servo) AC is ice
cold,

It has 123,000 miles, is white in color, never wrecked,
new tires, front brakes, (it needs rear brakes)
re-built Bose amps (has cd changer)
New timing belt,
wires,
plugs, cap, rotor,
door locks re-built
oil changes every 3-4k since new,
struts are good, but have 50+-k on them
diff oil serviced ever 20k
Automatic transmission

It needs a rear muffler, it is starting to go.

oh yeah it is white pearl. and it is located in Seattle WA.

thanks in advance

P