Would someone give me a round about estimate for installing 160 foot of 4' black drainage tubing? With about 3 foot going under a side walk? WOuld use a trencher but home owner requested not to b/c routing through the landscape! I estimated the cost of all material to be $110. I thought of placing a bid for Instalation for $570 completed! An estimate of $460 dollars of labor! Does that sound ball park?