I just go to Tractor Supply and see what they have. They carry a few brands of organic feed, but their stock varies. I haven't found much difference in them.
It's your decision to make. If you search out and eat other organic foods, then you should do it. The cost is higher, but remember, non-organic grain is most likely sprayed with Round-up. All corn fields which aren't organic are. so when you eat the corn, you're ingesting Round-up. Would you...