I've switched to this expensive litter from Swheat Scoop because of dust and
the worry about it being an allergen for one of my kitties.

Just to let you all know, my local petsmart, and perhaps all of them, has
dropped the price on the big bag to $13.99.

There is an imitation litter which is every bit as good and formulated the
same, and cheaper:  "Clump 'n Flush" that I find periodically at PetCo but
they suspiciously run out of it often.  Nature's Miracle seems to be the
same formulation but it is at least as expensive or possibly more expensive
as World's Best.