I hated eating really poor when we were at my mom's house. It was basically spaghetti, sauce, and a caesar salad (as in lettuce with dressing) every night, because that was all we could afford. Surprisingly, I did begin to lose weight on this. BUT. I felt increasingly sluggish, and had more and more trouble with how my body FELT. So...really, in the end, the weightloss wasn't important.

Have you thought about looking into Muesli? It's a different type of cereal, and you can even make it yourself if you have the right ingredients. Brian does Raw Oatmeal (with water, but not milk) for breakfasts when we can't get a smoothie together. Though, this is more for when you're deciding to make cereal part of the Daily Diet, rather than just cheapest eats.