A customer of mine recently decided to widen his driveway. To widen it he had a few dump trucks drop off some fill, for which closed part of the ravine for which the driveway now sits atop, basically he was leveling the land. Nonetheless he is concerned with heavy downpours that this new embankment may wash away and has asked me to reinforce it with some boulders, roughly 2 feet x 2 feet, 100-150 pounds or so. I am new to this type of work, and went to a supplier for rocks. I need enough for about 275sqft, which will equal about 3 pallets ($650 delivered), the biggest rocks he has are pennsylvania stone?, although some seem kinda small. Upon hearing that price I went to the local gravel yard, and the owner told me too just take whatever I want, I figure 75 or so rocks. Basically it looks like I will have to make the slope from the embankment less steep then lay the rocks on it, make it look like a jette in the ocean. Any thoughts? How much should I charge?