Price drop! 8K+ bought in past month. Amazon has the Winix 5510 Air Purifier (New Generation of 5500-2) for $136 - 25% off coupon (check "Save an extra" box, eligible on first S&S order for this product, can cancel anytime) = $102 with free shipping. Cleans rooms up to 1,881 sq. ft. in 1 hour.