Not much else can be said about this, best price I've ever seen. Better than the Cadbury factory store price.
Was popping into asda longwell green (Bristol) and was confronted by a huge display with hundreds of nine bar multipack flake, almost fell over at the price. Even double checked as they scanned to be sure.
I'm sure it's nationwide however don't know for sure, too busy eating chocolate.
Couldn't find it in a search, sorry if it's been posted before.