*Costco members Only* 3M 2200 Series Filtrete Filter, 4-pack (Various Sizes) $45.99
Costco online has 3M 2200 Series Filtrete Filter 4-Pack for $45.99 thats $11.50+tax each. Shipping and handling is included. MPR 2200 might only need to be changed once every 3 Months or so. From my experience this is a pretty good deal.