Not sure if petsmart is making a mistake but they have a 20% off anything online plus buy one get one 50% off on caribsea liferock dry live rock. https://www.petsmart.com/fish/decor-gravel-and-substrate/gravel-sand-and-stones/caribsea-liferock-dry-live-rock-64745.html.
If you get TWO boxes...
