192-pack of Great Value Alkaline Batteries AA or AAA $20.16 with Free Shipping!  At 10¢ each they don’t have to be Duracell! I use the cheapies for my mouse – given the amount of time I spend on the computer, I go through about one a week.  Also good for remotes.  I believe Great Value is the Walmart house brand.

Four, 16, 24 and 48 packs are also available.