Tracy Hengst found a good source for cheap batteries:
I get so frustrated when those books or toys that require odd-sized batteries need replacements. They are SOOO expensive and wouldn't you know that the package would only come with 2 to a pack and I'd need 3. So, one day I happened into the dollar store and picked up a package of batteries (5 or more to a pack depending on size) for $1.00! I'm not always able to find the exact match so experimented and have found that ones that are close in size have worked just fine. Sure, the batteries don't last as long as the name brands… but for the length of time the kids use the books or toys, it generally works out.
Ugh. Batteries. I cringe every time I buy them. We've made an almost complete transition to rechargables, but we still need a few odd sizes here and there. Does anyone have other suggestions for cheap battery sources?
Related: Simplify battery replacement