Cargill Salt Water Softener Red-out Pellets, 40 Lb bag $1.50 or lower B&M YMMV Walmart
Walmart B&M has 40 Lb bags of Cargill Salt Water Softener Red-out Pellets for $1.50 a bag with some stores @ $1. They also have Diamond Crystal® Solar Naturals® Salt Crystals for Water Softeners 40 lb. Bag for $1. YMMV
Stocked up since the prices were so low.