Some surfaces should never see high pressure. Shingles, vinyl siding, stucco, painted wood, and screens all get chewed up by a pressure washer. Soft washing uses low pressure and a cleaning solution that kills the algae, mold, and mildew at the root, so the surface comes clean and stays clean longer.
The people who quote your driveway are the people who clean it. No subcontracted crew showing up instead.
A specific number for your slab, in writing, that does not move once we are on site.
Pressure dialed to the surface so concrete gets cleaned, not etched. 5 stars on Google says the work holds up.
Tell us the address and roughly how much concrete you have. We will measure it up and put a fixed number in writing, for free.