Product review (5 stars): Great, Reasonably Priced Filter.
When you purchase a humidifier with this filter, it would be wise to do a little homework first so you know how expensive it will be to run the thing.  I did this and agree that these filters are expensive - but it was no surprise.  It is frustrating to see bad reviews of a perfectly good filter only because the people that purchased the humidifier thought it was magically going to filter itself.  Give me a break.  This filter does what it's supposed to and is reasonably priced for how large it is.  The benefits of having this humidifier well outweigh having to spend $60 a year to put filters in the thing if you value not waking up in the morning with dry nose/throat.  That being said, yes, this filter does need to be replaced every couple months in my opinion.  Some things I do to extend life:  every other week I soak this filter for appx 1 hour in a very weak solution of CLR and hot water in my sink.  Easy.  This removes the calcium deposits.  I then rinse the filter VERY well with cold water and put it back in the humidifier upside down from the way it was situated before.  I can typically get 2 months of life out of them before they start falling apart.  Buying in bulk is also a good idea.