This movie sounds like
The Burning.
http://www.imdb.com/title/tt0082118/
In it, the guy kills people with a big pair of garden shears. He does wear a robe-like outfit (but no hood). There's a scene at the end where one of the last survivors is climbing along a rock wall, and the camera pans up and you see the killers legs and his garden shears.
Also, the killer does do business from a burnt out stone building in the woods, and if memory serves me correctly, he's got some old chairs in there or something.