When you say the 'main prize' I'm assuming you're talking about the grand prize. It doesn't matter which choices you make to get them. The best you can do is try to spread out which types of ingredients you're using so that you don't run out of one and get locked on recipes.I am playing in 3 worlds. One I am advanced and consider the event buildings junk. And I have a city 11 days old and another 9 days old, both Iron Age. The event building is almost magical this early. And today's Special is the Cider Mill selection kit. That is garbage on my advanced world which I endlessly reject in AD. But it is just what I need most in my baby cities, and I really really want more than one of them.
That raises a question: how are odds of getting main prize affected by when you choose a 1, 2, or 3-ingredient recipe?