Amazon.com has Grenade Ration vitamin packs (30 packets) for $16.77 when you clip the 'Extra $10 Off Coupon' found on the product page and the additional 15% off by having 5 total Subscribe & Save items for the month. Shipping is free.
Item is approximately $35 before shipping at most sites.
Coupons are typically one use per account. You may cancel your Subscribe & Save subscription any time after your order ships.