I admit my mistakes. I've just begun to play with real money, and I was used to the more loose and dynamic games in play money. I was warned, playing real money is a different deal altogether.
Then, I must work on my self-discipline and better keep my cool when players play over-tightly. After all they were obviously afraid of me, seeing the monster in every move I made, I was leading in chip, and every hand would steal both blinds and ante from them. If I had kept my cool I would have won the tournament.
Instead of losing patience on their constant folding and checking, and take a huge risk by trying to go for the kill at the expense of my own chips, I should have fleeced them from their money chip by chip and take every occasion to steal pots from them.
I have no proof of collusion. In fact, I was on the button with the huge chip lead I'd fold to entice them to fight one another, hopefully to death, and often they bet and play against one another. If they were colluding both would have folded each time I did so.