Originally Posted by chas350
...but man they are not cheap!
It will depend a bit on how long it lasts and in how good of shape I can keep it. If it survives for 3-4 weeks of decent usage I wouldn't be too unhappy with the cost since it works well and seems to do a much better job of keeping my nose and lungs clean.
I also saw another brand (I think it was Stanley) at the big box store where I bought mine that was in the $2 range. Figured I'd try the 3M first and then maybe the cheaper brand later for comparison purposes.