Going Mobile? I'm a one man show here. I absolutely will not do work outside of my shop. Actually I won't go to a customers location for an estimate. Its mainly due to how much time there is in the day. I can barely keep up with the work I have now, much less try to work out of some unknown space. If I had the desire to deal with employees, I think I'd actually enjoy doing some on location work, and let the employees deal with the day to day stuff.
This requires an additional "service" charge — Fred Mattson
Look at what others in your area charge, plumber, electrician, HVAC,
your time is worth more than any of those guys. The last time I had to call a plumber 10 years ago or so, It was $90.00 minimum service charge weather he does any work or not. It seems high but when you consider time, fuel, wear and tear on your vehicle. $90 seems average, maybe even on the low end.
For sure raise your labor rate, $300 for 14 hrs. that's only 21.43 per hour. Compare that to any other skilled labor rate in your area. My starting/minimum price for a bow style headliner is 600 and that's at my shop. Obviously what can you charge depends on cost of living in your area and your reputation. I went 1 step forward and 2 back for so long, because I wasn't charging enough.