Well I guess if you don't mind paying a bit more I would say check pets mart or petco, if you have both stores near you I would suggest to go to each one and compare prices. You can also check online I guess but it's up too you.
Ferrets prefer a first-class kibble including cat food. Ferrets, just like cats, need taurin, which contains chicken. It won't hurt to treat your ferrets with real meat such as chicken, beef, pork or even shrimp.