Amazon has the 28-Count GoodSense Maximum Strength Chest Congestion and Mucus Relief (Guaifenesin Extended-Release, 1200mg) on sale for $8.17 - 5% off with Subscribe & Save (can cancel anytime) = $7.76 with free shipping on $35+ or with Prime.

• Generic of Mucinex 1200mg ($15 at Amazon for 28-count)