With orders of $25 or more, Amazon offers Prime members the CamelBak Podium Big Chill 25-oz. Insulated Water Bottle in four colors (Metric Mint pictured) for $6.93 with free shipping. (Non-members can spend $49 or more to qualify for free shipping.) That's $3 under our September mention and the lowest total price we've seen. (It's the best deal now in any color by $6.) It's made of BPA-free plastic.
Note: This item is part of Amazon's "add-on program" and can only be purchased with an order of $25 or more.
Update: Some colors are currently on backorder, but can still be ordered at this price for delivery when available.