it won't be worth squat if its not running, so if the cost of repairs is not much, i would repair it before you sell it. anytime i see someone selling a car and they say "it just needs this (tune, new fuel pump, spark plugs, etc) in order to run perfectly"---i automatically assume that they've tried multiple things to fix the problem with the car and it will be a HUGE headache for the new owner get running. the price i'd pay for that car goes WAY down. maybe they're being honest, maybe they know the car will never run right, maybe they're just exhausted with the car---i don't know, but i assume the worst. so, i say sell it running, or part it out and sell it as a roller.