I need help with a 300 sq. ft. bluestone patio estimate. I don't want to overcharge my customer who is an acquaintance. I also would like to make a decent profit. With excavation, materials and prep and labor I estimated @ $8,470. Bluestone is select grade and laid over stone dust. I figured a 3-3,500 dollar profit based upon bluestone cost of@3,850. x $22.00 per square foot. What do you think?