how much does it cost for someone to put up a retaining wall
1 Materials and installation for a stone retaining wall start around $25-$40 a square face foot and go up depending on materials, site conditions, and other factors. 2  It costs $1,250-$2,000 or more for a wall 30 inches high and 20 feet long.
1 Material and labor for a wood retaining wall runs approximately $20-$25 a square face foot (and there's usually a minimum charge for small projects), which would be about $1,000-$1,300 for a 50-square-face-foot wall.