you can also check on line at petsmart.com and see what there online price is and then print it out if it is lower than there in store price they will have to sell it to you for the online price per there store policy.
It works too...I have done this....and they never hassle me for it they just give me the look like....who told you the secret....lol. My local Petsmart was always 10 more expensive than petsmart online.