My company provided me with air purifiers last year, so I am selling the ones I got beforehand.
All of them come with BRAND NEW FILTERS

1) IQAir HealthPrp Plus - brand new filters 5300 RMB (or 4800 RMB if you don't mind a half used V5 filter)

The filters are new. You are pretty much getting the IQAir for free for the cost of the filters. The PreMax filter has about 100 hours on it, so its not quite brand new, but has 98% of its life remaining. As the V5 has about half its life left, I am planning on replacing it with a brand new V5 when I sell it to you, but if you are content with a half used V5, I'll take off 500 RMB from the price, selling it for just 4800 RMB

2) Austin Air Healthmate Plus 450 with BRAND NEW FILTER 6000 RMB

The 450 is the top of the line for large rooms as a full size air purifier,with the best filter that is rated to lasts five years (but I changed mine after two years, given the conditions in Beijing). It is much cheaper to operate than the IQAir, which requires much more frequent filter replacement. The filter itself is worth more than what I am asking, so its like getting the machine for free.

3) Austin Air Healthmate Plus Junior 250 with BRAND NEW FILTER 3500 RMB

The 250 is the top of the line, but sized for a small bedroom with the best filter that is rated to lasts five years (but I changed mine after two years, given the conditions in Beijing). The filter itself is worth more than what I am asking, so its like getting the machine for free.

I got a couple other odds and ends machines, but these three are the pick of the litter. Get yours before the really bad air comes back for winter. I also got plenty of extra 3M masks for both adults and children - more than I'd ever need.