Amazon offers the AmazonBasics AA Alkaline Battery 20-Pack, model no. LR06-20P, is available for $3.56 before Subscribe & Save, $3.38 with free shipping after ($0.17/battery).
Of note, the AmazonBasics AAA Alkaline Battery 20-Pack, model no. LR03-20P, for $3.24. Add it to your cart via Subscribe & Save to knock it to $3.08 and get free shipping ($0.15/battery).
These make great flash batteries or emergency batteries for cameras if you have a grip with battery tray. Be sure to cancel Subscribe & Save once your order ships to avoid being billed for subsequent shipments.