Parts, labor hours, shop supplies, "misc". Which line items are legitimate, which are padding, and the two questions that settle it.
Most repair quotes have four kinds of line items, and only two of them are worth scrutinizing closely.
Ask whether parts are OEM, aftermarket, or remanufactured — the price difference between the three can be significant, and a fair shop will tell you upfront which one they're quoting without you having to ask twice.
Shops bill against published "book time" for a job, not the actual hours a mechanic spends. Book time exists so quotes are comparable across shops — a job billed at "2.5 hours" should cost roughly the same labor no matter who does it, since the rate difference (not the hours) is what varies.
These are usually small, flat fees covering things like shop rags, degreaser, and disposing of old oil or brake fluid responsibly. A few dollars is normal. If this line item is more than 5-10% of the total, ask what it's actually covering.
This is the one line item worth pushing back on. A legitimate quote can itemize almost everything — a vague "misc: $85" with no explanation is the closest thing to a red flag in an otherwise normal-looking quote.
"Can you break down the labor hours separately from parts?" and "What does the shop supplies fee cover?" A shop that answers both plainly is quoting in good faith, whatever the final number turns out to be.