Okay, that one has obviously made the rounds, but this one hasn't--yet!
An old hermit decides to head into town to buy himself some supplies. When he gets to town he sees this giant store called WAL-MART (mind you, he's been in the woods a long time).
He goes in and has a look at all the bright shiny merchandise. He gets back to the hardware department and sees these newfangled inventions called "chainsaws" (like I said, he's been in the woods a looooong time). The department manager comes up to him and asks "Can I help you?"
"Sure, young feller," says the old timer, "I been a-lookin' at these here chain-sawers. What can you tell me about them?"
"Well," says the manager "These are some fine pieces of equipment. How many cord of wood can you cut in a day?"
"Sheeeeoooot, I can get out my bucksaw an' pile me up at least two cord a day," says the old timer.
"Well sir, I guarantee you can double that if you get you one of these here chainsaws," says the manager.
"You gotcherself a sale!" says the Hermit.
A couple weeks later, the Hermit goes back to Wal Mart and looks for the same manager. "Hey there young feller! This here sawer don't work like you said it would, an' I'm a-wantin' my money back!"
"Let me have a look at that," said the manager, and he pulled the cord and fired up the saw.
"WHAT THE HELL WAS THAT!!!!!" screamed the Hermit!
<shave and a haircut, two bits!>