What drives the price
Thickness (4" residential vs 5–6" for heavy vehicles), reinforcement, base preparation depth, and how much old material has to come out and go to the landfill.
Stamped or colored finishes add $6–$12 per square foot over a broom finish.
Where quality hides
Compacted base and correct control joint spacing determine whether the slab cracks in year two or year twenty. Ask what base depth and joint spacing the quote assumes.
Drainage matters — water pooling against the garage slab is a recurring, expensive problem.
Before you sign
Confirm concrete PSI, base depth, reinforcement type, joint plan, and the cure time before you can park on it (usually 7 days for cars).