Jack Daniels, George Dickel, Tulahoma, and Cascade, are all located in Coffee County Tennessee. They call get their water from the Tulahoma spring which is naturally devoid of mineral content making it absolutely perfect for whiskey making. If you drink directly from Tulahoma spring, as I have, you'll notice that the water is virtually tasteless. One can almost describe it as "sweet."
Coffee County Tennessee is a dry county, no alcohol sales or consumption allowed. Interestingly, alcohol giving is allowed, so Jack Daniels traditionally gives each employee a bottle of black label with their monthly paycheck and a bottle of Gentleman Jack for Christmas. Employees are admonished that consumption within the county is illegal... nudge, nudge, wink, wink.
Getting on ten years ago now, in a bid to increase tourism, Coffee County opened an exception. Each distilery is now allowed to make one special product that must be unique (not just a special label) which they can sell at the distilery, but only at the distilery. It has to be a distinctive and exclusive product. It can be sold at the distilery in Coffee County, but buyers must be strictly admonished that any consumption within the county is illegal... nudge, nudge, wink, wink.
I do seem to recall that the Jack Daniels distillery special product was a bit expensive. $300 seems a bit much. But maybe that's what you're thinking of. In that case, it can only be purchased directly at the distilery.