Winix 5500-2 Air Purifier with True HEPA Filter for $149.99 Shipped
Winix 5500-2 Air Purifier with True HEPA Filter for $149.99 shipped. Here is a screenshot for reference. Its Smart Sensors gauge the air and the auto mode adjusts the fan to filter the air as needed, along with with a sleep mode for night-time operation. Most places have it for about $249.
2 very similar deals were also reported by some other sources: