So if I am following the logic right here if you were to get a 1.36 gallon jug of 6% bleach for $2.25 then my equivalent cost is:

cost per pound (assumed same unit weight at your 12.5%) = 2.25/(9.7*1.36) = $0.171/pound

cost per available clorine = 0.171/0.057 = $2.99

maybe I had better shop around for a better price

Riles