This deal has ended.
Through 10/28, GNC.com offers buy one get one 50% off for Pro Performance and AMP brand products. For instance, Casein Protein (2lbs) is $31.99 or buy 2 for $47.99. AMP Wheybolic (3lbs) is $59.99 or you can 2 for $89.99. Shipping starts at $6.90 and sales tax is charged in states with GNC retail locations.