Right now on Amazon you can grab these Duracell Coppertop Duralock AAA Batteries 34 Count  for $15.99.
Just be sure to clip the $2 coupon in the middle of the page.
You can make it $15.09 with Subscribe and Save (on the right hand side of the page). If you use Subscribe and Save there are also NO SHIPPING FEES.
As always double check the price before you buy- Amazon prices change quickly!