I would suggest raisins or other dried fruit, cookies, peanut butter and jelly/honey sandwiches, a trail mix that doesn't have a lot, if any, nuts (if the protein bothers you), Chex mix, cereal bars, Payday candybars (although, again, the protein may bother you) and, of course, bananas. I sometimes made oatmeal cookies with raisins or dates and take those on a ride with me. I just follow the recipe on the Quaker Oats package. I also have a recipe for Oatmeal and Apricot cookies that is very yummy and easy. PM me if you'd like it.
I understand your desire not to spend a lot of money on things like Clif Bars and the like. I don't buy a lot of that stuff either. My only comment, however, is that the longer and hotter the ride, the more your stomach may have a hard time digesting "real food," especially as the ride wears on. Gels and other simple-sugar formulations (like Clif Blocs) can be rather helpful--if not necessary--in that regard. I've had a few tough rides this year where just the thought of eating something too substantial made me sick to my stomach. With that in mind, I almost always pack a bag or two of Clif Blocs and some gels just in case regular food doesn't agree with me that day. I don't always end up reaching for it, but it's nice to have it as backup on supported rides.
Good luck with your century!
Kate
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher