With orders of $25 of more, Amazon offers the BlenderBottle 28-oz. Classic Loop-Top Shaker Bottle in Clear/Red for $3.23 with free shipping for Prime members. That's $1 under our mention from last November and the lowest price we've seen. (It's the best deal now by $6.) This BPA-free bottle features a stainless steel wire whisking ball, measurement marks up to 20 oz., stay-open flip cap, gripper bars, and carrying loop.

Note that this item is sold as part of Amazon's "Add-on program" and can only be purchased with an order of $25 or more.