harrydavidson701l3 - Hi,nice to meet you.

vasile - I built the retaining walls myself. It was quite complicated, but it was all worth it in the end. If you're also thinking of doing it yourself, I would recommend you put a drain pipe behind it, so water that collects in the soil won't cause the wall to fail. Also, the base should be half the height, so 4 feet tall is a 2-foot footer, and you taper up to the top. Don't forget to tiebacks into the hill to tie the wall into the hill. I worked with some concrete contractors for the driveway, and they did it. I don't remember how much I paid, but it wasn't that expensive, to be honest. For more information visit https://www.almightyconstructionnw.com.