There's a lot of that here in Vermont. Integrity is the norm. In fact, the bank tellers actually apologize if they have to ask for ID! "I'm sorry, sir, but I haven't worked here long enough to know you yet. Would you have some ID I could see?"
I think at least part of the motivation for bartering is to keep things under the table. Most Yankees are loathe to give Uncle Sam more than they have to. But another part of it is a respect for your neighbors. The difference between an Old Vermonter and a newcomer is if the old timer has a tree fall across his driveway and you go to help, he thanks you and shakes your hand when the job is done. There is an understanding that if and when the tables are turned he will be there for you. The newcomer, on the other hand, whips out his wallet and tries to pay you. I don't like that way as much.
Pete