GearBest offers the 2nd-generation Xiaomi Smart Mi Air Purifier in White for $159.99. Coupon code "PURIFIER1" drops the price to $143.99. With $12.90 for shipping, that's the lowest total price we could find by $30. It can purify 380 cubic meters of air per hour and features remote control via the Mi Smart Home app.
Note: This item ships from China and may take two to three weeks to arrive.