Walmart offers the Honeywell True HEPA Air Purifier in Black, model no. 50255B, or White, model no. 50250-S, for $115 with free shipping. (Amazon charges the same for White.) That's $34 below our September mention, the best now by $50, and the lowest total price we've seen. Designed for rooms up to 390 square feet, it features a true HEPA filter, three cleaning levels, and 360-degree air intake.