In terms of bang for buck nothing comes remotely close to having a furnace filter strapped to a 20" box fan. This gets you most of the benefits of an expensive filter for a fraction of the price.
People will talk about CADR but also look at TCO.
People will talk about CADR but also look at TCO.
I still recommend just spending the 150 bucks on a Winex or Coway. Then you have true hepa, plus filters that last a year.