health is the easy way to a fool's wallet.
that said I have 3 expensive of those filter at my home. not that one, 3 other different brands. The main factor for my purchases were silence. and ironically the only one that was silent is a discontinued sharp model that sold for $150. all the $300 models are awful. specially the blueAir one that focus all it's marketing on being silent.
No it's not, especially with a preemptive health solution (solving a problem people don't feel they have).
and i wrote wrong! i don't have a sharp one. the silent one is from sanyo! it also has the ONLY truly silent humidifier included, though very low volume as it is only used for the ionizing shenanigans.
http://www.amazon.com/Shop-Fox-W1746-Fine-Filter/dp/B000QD7Y... is a good choice if you want a single large room done.