Hi Shais' Mom.
We don't have a Petco, but I know I saw that food at PetsMart yesterday. I can't find a price in today's advertisement, but it does have an ad about $7.00 off of the Science Diet food (35 pounds or larger). It should have an "on bag" coupon. Do you have Petsmart? I guess you could go online and find PetsMart too.
Good luck.