If the Champion costs more than 1.5x 8.25% per gallon, then it's a bad deal. If it costs less than 1.5x per gallon, it's a good deal.

For example, my local CostCo sells 3 121oz jugs for $9--which is about $3.17/gallon (gallon=128oz). But I but 5 gallons of 12.5% for $19 which is $3.80/gallon. As long as the 12.5% is below $5.55, it's a better deal than the 3 jugs from Costco.