Just got back from looking at a client's yard where they want to have a retaining wall built. The dimensions are 75' by 3' tall above ground. I know that I will need to have the area dug out with a mini ex and set the foundation and go from there. My question is what are you guys getting on average per linear square foot? Also, although this is a relatively low wall, do you think i need geogrid since it has erosion? I am relatively new to doing walls but want to learn. Here are some pics. Please let me know what you think.