Wow. $400 for 20 plows? Where do you live? Sign me up for that.
Here they get $150 or so for 2 inches and it goes up by the inch. Kind of expensive if you ask me.
One guy quoted me $125 for 2" and $15 an inch over that. Snow drifts and snow plow piles are extra to break up.
They charge extra if anything has to be shoveled because they cant plow it fully.