Today only, until 9 am ET (or 100% claimed), Amazon offers Prime members the Energizer Lithium AA Batteries 10-Pack for $14.99 with free shipping. (Non-members can spend $25 or more to qualify for free shipping; otherwise, it adds $5.37.) That's $1.50 per battery and the lowest total price we could find for this quantity by $5. They purport to last up to 9x longer than traditional alkaline batteries.