Bought new from Target about two years ago for ~$150, makes a huge difference for my dust allergies, runs pretty quietly. The only reason I'm selling it is because I'm moving across the country - this thing is awesome. New filters run about $25 from Target, and the filter was changed about 3 months ago, so it should be good for several more months. It's similar to this one: http://www.target.com/Honeywell-Permanent-IFD-Tower-Purifier/dp/B000CQV2ZY/