Quill offers the Windex Powerized 32-oz. Glass Cleaner, model no. 90135, for $1.99 with free shipping. (Staples charges the same via free ship-to-store pickup.) That's the lowest total price we could find by $3. (For further comparison, we saw a 2-pack for this same per unit price in February.) Sales tax is added where applicable.

Of note, also available is the Mr. Clean 28-oz. Multi-Surface Cleaner in Summer Citrus Scent for $1.99 with free shipping. That's the lowest total price we could find by $6.