I think $300 is a bit high for the initial service call, considering the amount of time it took the tech to find the leak. A plumber had already detected no leaks inside the house, so a lot of guess work had already been completed.
Located a water pipe leak. Floridaleakpros.com
Located a slab leak that flooded two rooms. FloridaLeakPros.com
Leak detection, looking for the cause of water flooding home. Found ac drain leaking and got them back up and running! FloridaLeakPros.com