UPDATE 07/07/14: Price for the 3-pack Silk Organic Soymilk has increased to $7.29. Unit price is $4.86/gallon. Item number 395983. PUBLISHED 06/20/14: A weekly item in our cart, the Silk Organic Vanilla Soy Milk, comes in a 3-pack of 1/2 gallon (64 oz) cartons. It’s priced at $6.99 for the 3-pack. Item number 395983. Unit … Continue reading Silk Organic Soy Milk – Costco vs Safeway