Unlike you, the mechanic will have a lift and air tools. It will take less than an actual hour to do one control arm. But he bought a lift, rents the garage, bought really good tools, and does this kind of thing all the time.

Of course he will pad the actual time, so would I. Unfortunately, the 'book' time is probably 2 hours or more: trainee mechanic, no power tools, 15 minutes just to get the car on the lift without having it fall off, rusted bolts, never been there done that before, coffee break, three pairs of latex gloves, etc.

Don't forget, if the shop is rented and/or is in a high tax area, the labor charges increase. Same for shops that specialize in foreign cars, just because they do.
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My back feels better when I sit in a Volvo seat