Ford Repair: Idle Air Control Valve, air control valve, explorere

Question
Hi James,
 We have a 1998 Ford Explorer XLT 4.0L EFI. I have been dealing with one mechanic and he has been good I thought to this point. I think he is over pricing at this point.  The Explorere was running rough and I hoped only plugs. I bought the plugs but ran into a problem replacing them. so iI took it to the mechanic. He "diagnosed" it and determined it also had a bad Idle Control Valve.
He put in the plugs I had and replaced the valve for a charge of $356.30. I think that is very high as the valve is very simple to replace. Is this charge resonable?
Thanks,Rocky

Answer
That sounds reasonable. Changing the plugs themselves is pretty labor intensive. The IAC is another fairly intensive part to replace. Even though thee part is 50 dollars at the parts store, you were charged more just in case the part is ever defective. The garage has to replace the part themselves and eat the labor. You didn't state whether or not they replace the plug wires as well, which I assume they did. What they also did, more than likely, was to clean the throttle body out while replacing the IAC. Most of IAC problems stem from dirty throttle bodies. Look at my last few idle related posts, and you will get some insight into what the mechanic did to clean it out.