Whole Foods and online bulk health-food sites sell Quinoa Flakes, which I've tried and enjoyed. They're sold by the pound on nuts.com, running something around $5-6/lb. I don't buy them, personally, since the cost seems a bit steep and I have felt no need to eat anything cereal-like, but the product does exist!
You can also just cook regular quinoa, then add milk/cream/coconut milk and cook some more to make a quinoa porridge. Pound for pound, whole quinoa is cheaper than the crushed/rolled flakes.