Amazon offers Prime members the Nalgene Tritan OTG 24-oz. BPA-free Water Bottle in Slate Blue, model no. 341902, for $6.81 with free shipping. (Non-Prime members can spend $35 or more to qualify for free shipping; otherwise, shipping adds $5.58.) That's the lowest total price we could find by $4. It features 1-handed operation and fits in most bicycle water bottle cages and backpack pockets.