Meh.com offers the Rayovac AAA Alkaline Battery 48-pack for $6 plus $5 for shipping. That's the lowest total price we could find by $3. These batteries can purportedly last unused for 10 years.
Also available is the Rayovac AA Alkaline Battery 60-pack for $8 plus $5 for shipping. That's the lowest total price we could find by $10. These also are purported to last unused for up to 10 years.
Of note, at checkout you can opt to purchase a monthly $5 VMP Membership, which bags free shipping on your current order, and orders made within the next 30 days. Since it costs as much as the $5 shipping fee, you may want to consider this option if there's any chance you'll buy something else from Meh.com (even though they'll do their best to talk you out of it). However, it is an automatically-recurring charge, so if you're not going to shop at Meh.com, you'll want to cancel it before your 30-day period is up.