I've noticed this a few weeks ago instore and wondered if they were clearing out stock or maybe not popular, as all the other Keri premium and non premium were not discounted this cheap.
I bought several at the time, then earlier in this week I saw in store again at the same price for this flavour only so bought some more.
Not sure what the deal is with this premium flavour being discounted so much, but I like it and is very cheap.