Started making my own granola bars last week. Its been really easy, cheap, and rewarding like you said. I've also switched to making sandwiches for longer rides to replace some bars and stuff, mainly whole wheat bread, crunchy pb, bananas and/or apples, and honey. Its been an awesome experiment to say the least. We could exchange granola bar recipes (NH haha) if you want. I have a couple combos that have worked.