Everybody is different, so it's about what feels right for YOU. But, yes, math is involved. You have the book by the balls.
I have Michigan to win it all...300 to win 2,800.
There's a reason why I played Michigan. Loved the way that team was playing and loved its draw. In fact, I'm adding two units on Michigan to win its semifinal game.
If it does that, I will then put 2 units on the Villanova/KU winner...this will guarantee me a 1 unit ($300 profit).
Do any of your books offer a prop "Kansas vs. The Field" right now? You can play The Field right now, but it will severely eat into your potential 2000 profit should KU win it all. I would wait until AT LEAST halftime of your semifinal game to hedge...but that's just me.
It sounds like you are confident that the winner of that semifinal will win it all. You may be right, but you may be wrong.
Good luck with whatever you do!