15 Minutes ? NOT . On a 6 zone system , first you have to unroll the hose and locate the backflow , 5 minutes if you know the property . Second you knock on the door to have customer open garage . 5 minutes . Turn off water inside 5 minutes . Hook up , start compressor and blow out 3 minutes first zone , 2 minutes each zone after 15 minutes . Rollup hose and give bill and wait for payment , another 5 or 10 . You are looking at 1/2 hour average stop . Include travel time and you are at 45 minutes to an hour per stop . And yes where I am from $45 is a lowball , $95 is on the cheap end and $125 is the larger companies . For a 6 zone . $45 is what we were charging 30 years ago .