it was a seminar. there were only 3 or 4 landscapers there. everyone else was a homeowner who wanted to learn how to do it themselves.
The digging wasn't as bad as it looks like. the problem with using a machine is that you'll spend just as much time fixing the damage the macine does as with just doing it by hand. each shelf has to be cut out to 90-95* and nice and level all the way around. I suppose a dingo or similar might be alright to use, but a mini-ex would do more damage than good i think.
Efficiency = Profit