Updated. Amazon lowers the price of 24 Packs of Slim-Fast Optima Ready To Drink Shake 11oz Cans in Creamy Milk Chocolate flavor from $34.99 to $19.56. Choose "Subscribe & Save" to drop the price to $16.63 with free shipping, and at checkout enter code SLIMMMAY, which cuts it to $14.67. Slim-fast is a great way to shed some holiday pounds, and this is a great price to help you get started. Note that you'll have to cancel your subscription if you don't want additional shipments. Sales tax is only charged in KS, KY, ND, NY, and WA.