City of Philly?

You already know the competition you'll be dealing with, range from well established units to "side job" union guys, to hackers in station wagons with extension ladders strapped to the roof.
Going rate could be as low as $20/hr depending upon the job, and the location.
We stay away from city work because of all the crime, and that alone you have to factor in to your rate....1 guy to watch the truck, 1 to do the work...
I'd look at what niche area your after, ie..Main line area or SE philly, there would be a big difference in "going rates" in different areas...

All IMHO, mind you..

Good luck...

Dnk...