The amount a shop is going to charge you often has little relation to how long it actually takes. They're there to make money.

I knew a kid changing turbos in Mk4 VWs on his lunch break. He had time to drive home, replace a turbo, and drive back to the shop.

Shop was still going to charge a few hours.

Labour last time I had front shocks and struts done? 3 hours not including the alignment.

Friend's brake job? 2.5 hours - they were 4 wheel disk, what was the mechanic doing for the other 2h?