the 603 powered cars are nice, tedious to get running right, and still have plenty of power.
I think $800 would be flat stealing it... 1500 is more fair. if it's REALLY clean, rust free, and you feel the mileage is accurate from personal examination of the car, the a/c shouldn't lower the car below 2500.

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!