Most of the time a excavation contractor can dig the stump out in a hour a rubber tired hoe would be 100-120 dollars. No one in this area grinds stumps because a backhoe or mini excavator can dig them out. The reason why someone wants a stump removed is its in the way of landscaping.
The ground and soil here is very rocky you can dig down 6 inches and you will hit football size to size of a car rocks. With tree stumps is the tree is sitting ontop of the rocky soil it would take those grinder teeth right off.
I was flush cutting a stump for a person it was about 30"s in diameter cutting 1/2 way through and the saw wasn't cutting anymore. Pull the saw out and the teeth were all chewed off its what the h*ll. I found out there was a hidden rock in buried in the middle of the stump.
Now when some one wants me to flush cut a stump its minimum 6" above the ground.