I need to make a price on a job that I haven't done before that involves digging a trench about 160' long & about 16" to 20" deep by about 8" to 12" wide. It is to install a 6" pvc drainage pipe for the building gutters. It is to be dug across a pretty level gravel parking lot. I have a backhoe attachment for my bobcat but I'm wondering if I shouldn't rent a trencher for this job. I think it wouldn't make as big of a mess and would be quicker. I haven't mastered the backhoe yet anyway. Any ideas on how much time and how much I should charge? I appreciate your advice.