Not exactly stockpiling, but I was for a while saving up my fuel points, then filling up a series of gas cans at the end of the month where I'd use all my fuel points at KS and buy two fillups or a bit more worth of gas, and then refuel the car from my cans. Guess it saved a little bit, but probably never recouped the cost of the jerry cans.
Only real way to go bulk for gas is to have a storage tank at your home and buy wholesale from a fuel distributor, IMO.