One way to save money: get your water from the tap, not the bottle. It's no different.

...sed dicimus quod terra et aqua sunt elementa, quia haec non componuntur ex aliis corporibus, sed ex ipsis est prima compositio corporum naturalium.

So says this editorial:

The Environmental Working Group released a report Wednesday that charged that some bottled waters were “no different than tap water.” And it found fertilizer residue, pain medication and other chemicals in some major brands.

While a lot of bottled water may be as pure as promised in those alluring commercials, the real problem is telling which is which. Public water supplies are regulated by the federal government. Not so for bottled water. The Food and Drug Administration does have some oversight, but bottled water is not very high on their long list of priorities.

Of course, that's the United States. Your country may vary.