What is the labor cost per square foot for a keystone wall?

The biggest cost of a retaining wall is the first course. Is it dug by hand or with an excavator? Is it in loamy dirt or is there a lot of rock? Can you stack the block with a tractor or by wheel barrel. I recently completed a Keystone Legacy wall (60 face feet) which block is 6 inches high and 16 inches wide. This was done on a compacted base. The wall had to be put in next to an existing fence that was covered with up to 30 inches of dirt. The purpose was to correct dirt being back filled against the wood. I used a small excavator to remove the 25 feet of dirt and also had two laborers. 4 Man hours.

Picking up block was one hour. Moving a hundred blocks took 2 man hours with the tractor and one laborer. The first course averaged 10 minutes per block to set and level. The second laborer followed behind and added up to 6 layers of block. Two skilled workers spent 4.5 man hours setting the wall. Back filling, setting up tractor rounded out the job to 18 man hours total. Material cost $6.30 a face foot and labor was $14.67 a face foot. I would consider this job easy only because the dirt was soft and I used the excavator. My client added another 60 blocks and the cost per foot came out higher as we had a shorter wall.