Amazon offers the Winix True HEPA Air Cleaner with PlasmaWave Technology, model no. WAC5500, for $129.99 with free shipping. (Costco charges the same for its members.) That's tied with our mention from last fall as the lowest total price we've seen. (It's a current low by $59.) It's purported to capture 99.97% of airborne pollutants and allergens.