Amazon has the 120-count Hefty Slider Storage Calendar Bags (Gallon, 4 boxes of 30 each) on sale for $18 - 25% off coupon (check "Save an extra" box, eligible on first S&S order for this product) - 5% off with Subscribe & Save (can cancel anytime) = $12 with free shipping on $35+ or with Prime. Just circle the inital date of storage on the bag with a marker.