Amazon offers Prime members the LifeStraw Personal Water Filter for $14.99 with free shipping. (Home Depot charges the same via pickup.) That's tied with our mention from a month ago and the lowest price we could find now by $4.

This award-winning, BPA-free device enables you to safely drink contaminated water. It removes almost 100% of waterborne bacteria and protozoan parasites and will filter up to 1,000 liters of water.