First is the obvious, buy on sale. You'll see BOGO sales once in a while or 3-day sales and those can help. You can also shop your local bulk buy stores like Costco or Sams Club and get some there.
My personal favorite, however, is a bit different. It's ordering it in 40lb cases but the price can not be beat. The price is lower than anything in the stores but you have to buy a 40lb case. It's completely antibiotic and hormone free but you have to buy a 40lb case. There are no preservatives, no chemical additives, no water dilution and it's not frozen but you have to buy a 40lb case. If you have heard of them before I highly recommend you check out Zaycon Foods!
Zaycon offers a small variety of foods and each food item is available only a couple times a year. You will have to package it into normal size portions but again, the price and the quality are really unbeatable. So ask a neighbor or family member to share a case with you and order away! :)