Guardian Technologies Air Purifier (model AC4825E) - $50 (daly city)

Description from Amazon: GermGuardian Air Purifier with HEPA 13 Filter, Removes 99.
97% of Pollutants, Covers Large Room up to 743 Sq.
Foot Room in 1 Hr, UV-C Light Helps Reduce Germs, Zero Ozone Verified, 22", Gray, AC4825E Not heavily used, at most a few months during one winter season.
Filter is still in good shape, but probably should be replaced (per instructions).
Replacement of filter is factored into the price.
$50 OBO