Ph and alk adjusters can be purchased at big boxes and similar places for really good prices, too. The ingredients are identical- they're just put into larger containers for pool use.
I've started to use muriatic acid to adjust my tap water on refill. Otherwise I'd be adding over 20 ounces of Ph decreaser- I only need a cup or so of the muratic acid, a gallon of which costs about $2. So I'm saving substantial money and adding less stuff to the water.
And I still have all my fingers, toes, eyebrows and hair.
Sam's club offers a large pail of dichlor, cost comes out to less than $1/pound, but you get a really large amount of chemical- somewhere around #75. Not sure if this stuff has a shelf life or not.