I could use some advice on a small job because I have no idea how long it is going to take or what I should charge: A customer wants to replace 2 small palm trees that are in small beds (aproximately 3 X 3 each) filled with rocks. I reccomended replacing the rocks with mulch to keep the grass out because apparently the spaces in between the rocks are too large and this causes a real problem with grass coming up around the tree. In fact, the customer said he killed one of the palms because he was trying to get rid of the grass around it and sprayed roundup on it. I have heard that I need to have 3 inches of mulch to keep the grass and weeds from coming up again, so my estimate will be based on enough mulch to cover at least 18 square feet, 3 inches thick. The customer wants 2 "Sago Palms", 5 gallon size. Is this enough infomation for a rough estimate?