I am putting together an estimate to install 4" x 12' pieces of metal edging for a customer. 350 linear feet total. Just wondering what you guys estimate the time for one piece to be installed in hard clay so I can come up with a install time per linear foot. Is a bed edged the best way to trench? Any other help is appreciated, I haven't installed edging before, but I am very comfortable with an edger. Thanks!!