This Kiinde Breast Milk Storage 6 oz Twist Pouches 40 Pack is on sale for just $6.99 (Retail $14.99).
These twist pouches allow you to collect, store, prepare and feed all while using a single reusable pouch. Each pouch features a secure threaded cap that eliminates the risk of leakage and the pouches twist lock onto pumps from ALL major manufacturers (using the appropriate adapter which is sold separately). The bags are pre-sterilized as well.
Shipping is free with Amazon Prime or your $25 purchase.