Must be a national price. I just picked up the twin pack of comp K at Costco in Chicago (Lincon Park location) and it was $13.39 ($16.89 less automatic rebate of $3.50 as others have noted).
I suspect comp K may actually be a replacement of regular K if it is the only thing that stores like Costco are stocking. I realize Chris' article stated that this is a "companion" product, but I'll be interested to see how many large format stores (Costco, Walmart, Home Depot, etc) stock only comp K once we are in the middle of the summer.
Once regular K becomes "hard to find" then comp K has become the de facto replacement.