Could be a froze up throttle cable but mechanic should have checked for that. Otherwise thats the going rate for that pump. Will want to make sure you get a pump for a 4220 and not a 3820. Electronic manuals are screwed and got the part numbers messed up. I always consult my paper manuals for the correct number. Pump manufacturer has a contract with Kukje that keeps parts for the pumps themselves out of the hands of injection pump rebuilders. Make sure that the lever on top of the pump that has two cables attached is moving back and forth between the stops for it.