Master Switch -1986 GMC S-15 Jimmy

GMC Jimmy

1986 2-door GMC S-15 Jimmy: Driver door window switches fail intermittently. Mechanic wants to charge $145 for new master switch + $75 for 1/2 hr. labor. How do I know if this is “over-repair” to make extra bucks at my expense? Is it the Master Switch? New part for 25 yr. old car?