If I could not afford to feed my girls, I would go to local restaurants and ask them if I could take some of their trash. A lot of perfectly good food is thrown in dumpsters, and your chickens can benefit from that. Many restaurants will be more than happy to have you take out their trash because they pay by the dumpster, so if they can get rid of the trash another way, they can save $$ if they can reduce the number of dumpsters that are picked up.
Also, let your friends and neighbors know that you welcome their scraps and unwanted leftovers. Rather than having them throw away that box of moth-infested oatmeal, they can give it to you for your chickens.
the only problem with this is you may get more than your chickens can eat. Of course, the only solution to that problem is to get more chickens, right?