Any idea what the dealer would charge for replacing thermostat and flushing coolant?

I didn't get any replies for my last question, but hopefully I will for this one. From talking to some mechanics and consulting Google, my car likely needs a new starter control unit. About how much will this cost installed and can any mechanic do it or do I have to take it to the dealer? Thanks in ...

I've been having some trouble for about a week with my plastic key on key fob sticking in the ignition. Tonight, it would not come out, and as I jiggled and pleaded, it BROKE at the base! I can still turn the key if I fit the broken pieces together like a puzzle. It's the only key I have, bought the...