I am getting ready to start an addition on my house.32x28 with a basement under it.I am putting a Quadra fire 7100 fireplace in and there is a guy at work that has enough cultured stone to do a 6'x10'x2'..Gona look at it tomorrow but he said it is kinda gray limestone looking. He started doing his fireplace and got about 2' done and changed his mind and went another direction. Whats cultured stone going for? How much would this be worth?