Don't have any idea what the market is like in your area, but here in Oregon, unless the Cockerals are exceptional SOP wise they are not easy to sell. On Craigslist I advertise and see others advertising for $5 - $25 depending on quality. Check your local Craigslist. We have a local auction, they take 35% but if I have an excess from breeding, I can take 15 - 30 at a time, just drop them off and they all sell. Depending on who is at the auction that day (it runs every Tuesday AM year round) I get $4 - $12 a bird. They all get bought for butchering by the local Asian and Russian residents. Maybe you have something like this close to you? We also have several local "Chicken Swaps" and can sometimes sell them there. Mostly we do our own butchering unless we just have too many or are out of freezer space.
IMO I think what you are feeding them is just fine.