That price is actually pretty decent for Mazuri. Where I get it, I pay $14, but my parents get it at a place that charges $24 (both for the 25 pound bag). If I decide to move back up north, I am finding them a different supplier. But yeah, it's just more expensive in general.
It all depends on what your chins do good on. I've gotten in several chins lately that have been on different feeds, Shoots and Tradition, and I've been surprised, I weighed the whole herd again and though they were good weights to start with, several of them have gained some weight on the Mazuri, and it's what I can find locally, so I'm happy with it. But it does depend on how the chins do on it.