Spots 
The Shark NeverChange air purifier is already affordable, but this 40 percent discount makes it an even better deal. Like other models in Shark's NeverChange line, this model boasts a five-year filter lifespan when used and cleaned as recommended, potentially saving hundreds of dollars on replacement filters. NeverChange Air Purifier Max
Like the model above, this purifier boasts up to five years of filter life and features a cartridge to fight smells. It's $130 off right now, the lowest price we'll see until the holidays. Photograph: Molly Higgins BreatheClear MAX with NeverChange Air Purifier
This purifier's filter lasts up to six years, and it has an updated LCD screen with insights into the surrounding air. This includes metrics on current and historical air quality, temperature, and humidity; plus pollutant information, including measurements for PM 2.5 and 10, and VOCs. Photograph: Molly Higgins Photograph: Molly Higgins Photograph: Molly Higgins Photograph: Molly Higgins Vital 200S-P Air Purifier
This is my favorite budget air purifier. It automatically engages whenever pollutants are detected. Plus, the intuitive connected app helps monitor air quality and control the purifier while you're away. It's also got a HEPA filter for pet hair and dander.
This heavy-hitter is a whopping $366 off right now. It's quiet for its size and can clean the air four times per hour in a 1,000-square-foot space when running at its highest setting.
The Shark NeverChange air purifier is already affordable, but this 40 percent discount makes it an even better deal.