i got a call to build a retaining wall on a sandy hill. The hill is about 9' at the highest point (a small section) and it is averaging about 7' high. Ofcourse i want to do a 2 tier wall, but is the sand going to be stable enough to hold the weight of the stone? Should i pour concrete w/ rebar as my foundation or will limestone rock be sturdy enough? I planned to build the bottom tier 4'high. Then on the top tier, i would go along the contour with the stone and build it as high (5')or low (3')as needed . There are some spots that will get filled in to keep it from looking "jacked up". BIDDING: This is going to be a rather large project, but bidding it is new to me. I figured that i need appx 2100 blocks (16"x6") or 1440 ftsq of the blocks. This is going to be a cost of $18,750 for the customer. I'm thinking that i will double this price and that will include digging the hill and foundation, pouring foundation, laying the stone, back filling, laying perforated pipe, ect. This should take a week to finish with a couple of guys helping. What do you think? Decent pricing plan? or not? Any tips on the job are appreciated too.