You probably might want to look at Macy's or JCPenney for sales on California King bed sheets because from time to time Macy's does have a Home Sale where they have bedding on sale and in JCPenney they do have sales on bedsheets and also look in the clearance section of Macy's because you can find good deals on bedsheets. You can also try Kohl's too and see if they have California King bedsheets
Hope this helps you a lot,
Dodger