Walmart offers the Holmes Dual Blade Twin Window Fan for $17.88 $17.97. (Amazon offers it for the same price.) Opt for in-store pickup to dodge the $5.99 shipping fee. That's tied with last week's mention and the lowest price we could find by $2. It features twin 6" blades, adjustable extender screen, extender panel, and two speed settings.

Update: The price has increased at Walmart; however, Amazon still offers it for the same price with free shipping for Prime members.