Here is a $3 off Boost coupon (check under “Beverages” on the left side). You should be able to use this and get 50% off at retailers like Target or Walmart. Here is a hot deal if you have a Rite Aid in your area:
Boost Multipack 2 for $12
Use $3 off printable HERE, use 2
Get $2 +UP Rewards when you buy 2
Final Price: $2 each
Thanks, Common Sense with Money