Military Vehicle Repair: cost of repairs, ford taurus, 1989 ford taurus

Question
What should the cost of the repair of an alternator and a cellenoid switch cost?  This is for a 1989 Ford Taurus.  
The problem was that the car would not shut off even after the key was put in the shut off position. The belts and all kept spinning and turning and screaching also. The starter was replaced a month ago. And also in February of this year I replaced the battery.

Answer
About $150 should cover the alternator and the solenoid.  What solenoid though?  Kind of strange that both of these would be grouped together, but O.K.  You describe several problems here, screeching belts is one,car not shutting off another, alternator replacement a third battery and starter are fourth and fifth.  So, I'm not sure what you are asking, except for the cost of the alternator/solenoid replacement.  I hope this helps, but write back if I missed the mark.