Here are a close up of the prices and quantities.
Note that the $0.35/gallon in going into my
containers comes to $1.75 for all five gallons.
That little 20 oz. bottle of water is $1.25.
Realistically, you'd never even carry around gallon, so convenience factor to make this work you'd need a personal container. Seriously they're sold everywhere...you could even reuse an old water bottle. Plastic, glass or metal, they can even coordinate to your outfit if you so desire. That of course hearkens back to the time when carrying around a bottle of water was a status symbol...probably same time that a Starbucks cup made you feel cool.
Just remember strictly by these figures you're paying nearly 5 times the amount for your water in the little bottle that will sit in a landfill til your great great great grandchildren die. Need me to do the math? 1 gallon is 128 ounces. At 35 cents a pop it's under 4 cents per ounce. That 20 oz bottle at a dollar and a quarter is 16 cents an ounce. That's not even the cheapest Glacier machine around (about three miles away another grocery store has $0.30/gallon) nor is it the most expensive bottled water (god help you if your water is shipped from Fiji, France or hell Bling H2O for that matter). Seriously, check it out, it's a $40 to $60 for a bottle!
I'm not even that big of a penny pincher nor am I any kind of big environmentalist, but these are things I wish folks would really think about every once in a great while.