Menards is where I've been buying stuff for the past couple of seasons, especially the BOGO sale. I agree it's a great value. I'm just trying to avoid generating so many empty plastic jugs.
(For these purposes, I will conveniently ignore the obvious point that the best thing I could do for the environment would be to *not* have a big honkin' heated pool in the back yard. I pick my battles...)
I just got off the phone with Sunset Aquatech. The are close to my office, so I thought I'd get some info as well. They charge $17.25 for a 5 gallon bucket and a $12 refundable deposit. The lady stated that the Chlorine is 12%, but they have to label it as 10%. So at $3.45 a gallon it is cheaper than Menards normal price of $3.99 and achieves your goal of less plastic jugs. I'm too much of a tight ass and will wait for Menards BOGO. Have a great day and GO BLUES!!!