I generally prefer to go for bigger breakfasts, simply because breakfast is one of my most favorite meals of the day, but also because I never know when or if I will get enough time to grab a lunch, so it's nice to fill up in the morning and be full through lunch in case I cannot get any time to grab a lunch. Plus I can always dial it back and get a light lunch if I am still full from breakfast by the time lunch time rolls around. One of the other benefits of eating a big breakfast is that the breakfast food items themselves are often some of the most inexpensive meals to make. Some eggs are a far cheaper protein than a steak or some chicken breasts. I mean, two eggs, a potato (which I will cook into home fries) and a couple slices of toast, and maybe a couple links of sausage is less than a couple bucks total, perhaps even under a dollar if I do the math. Even home made Belgian Waffles in your waffle iron are dirt cheap to make and super filing.
The only thing I try to watch out for when eating in the morning is to not get too carried away with coffee, since it goes right through me for some reason, and I will inevitably be in the bathroom all morning. Strangely water, juice, soda or tea don't do that to me, but coffee does.
I'm happy with some good whole oat porridge, or fruit and fibre cereal, something that will keep me going until 12 but isn't too heavy either.