Amy,
I honestly don't buy that much bottled water.
We have 4 daughters who played soccer and learned real early how expensive it can be. In fact we used the big pop bottles in the freezer filled 3/4 with water that froze. You added water before practice and the ice slowly melted and kept the water cold. Gosh haven't thought of that in awhile. Had to be careful how you opened the freezer or they could fall out.
We are lucky that hubby can drink regular water.
We do refill the bottles but try to limit the number of times. I buy 2 six packs once a month and dispose of the old bottles. Worry about the chemicals from the bottles breaking down over time. Maybe I am overly paranoid but won't reheat food in plastic takeout containers either.

I was asking about the prescription for those who need water with them on a consistant basis. We have been caught without and have paid $2.50 for a small bottle.
Totally agree with you that the cost is higher than gasoline.
Great suggestion for a purifier.
Thanks Amy

Maggie