A mobile mechanic's price has two parts: the parts and the labor. The parts cost what they cost; a mobile mechanic buys from the same suppliers a shop does, often the same NAPA, AutoZone or O'Reilly counter. The labor is quoted for the job, based on how long that repair takes on your vehicle. That's it. There's no line for the building, the lifts, the service writer or the lobby coffee.
What you're not paying for matters just as much. No tow to get the car to a shop. No diagnostic fee that vanishes if you decline the repair. No shuttle, no rental, no afternoon off work. When people compare mobile mechanic cost to a shop estimate, they usually forget to add those to the shop side.
Every mobile mechanic on Mobile-Car-Repair.xyz quotes before the visit, and the number you approve is the number you pay. This page explains how that quote is built and what changes it.