This deal has ended.
Get 50% off most Filtrete filters right now at HomeDepot.com. For example, this Case of 12 Filtrete 20" x 25" Allergen Reduction Filters drops from $119.64 to $59.82, getting you each filter for only $4.91! They're going for $10 each in similar sets (see Amazon). There are over 100 varieties to choose from (go here and click on the "50% Off Air Filters" box). Shipping is free over $45, or ship it to your local store for free. Sales tax is charged in most states