At $3.15 with Subscribe & Save it's basically as cheap as it gets, previous $3.15 deal. However minimum purchase quantity is now 2.
Edit 6pm - Soy Milk Sold Out Amazon. Almond Milk still available.
How to get free subscribe & save delivery without prime?
Edit: It's been discovered you must have an active subscription to receive free delivery with sub & save, you can reactivate an inactive/cancelled subscription if need be. See here
Click on "First Delivery on 'Day Month'" and ensure "Get it with your next Subscribe & Save delivery, with 10% savings and free shipping." is clicked when selecting subscribe & save; if you don't have prime. You can also select your subscribe & save date here. Once your item has shipped, it's safe to cancel your subscription here.