Amazon has the 24-pack AmazonBasics AAA NiMH 800 mAh Precharged Rechargeable Batteries on sale for $16 - 5% off with Subscribe & Save (can cancel at any time) - 10% off coupon (check “Save an extra” box, eligible on first S&S order for this product) = $14 with free shipping on $35+ or with Prime (extra 15% off for 5+ S&S orders). Roughly 51 cents per battery. Can be recharged up to 1000 times.