The three small stacks mean that finishing in the money isn't too much of a worry if you aren't too careless with this hand.

450 isn't a massive amount (less than 1/6 of your stack). However, his position, aggressivenesses and stack being the only one to do any real damage prevents me from going allin preflop here.

I would do one of two things.

1. Call. If you hit an a A or K, you must be favourite to take what would probably be a very large pot. If not, let it go unless he shows a lot of weakness, you do have position as well.

2. Raise, but not allin. A raise to 1000 will signal that you have a very good hand and his reaction should be a good way of gauging his. You now appear even scarier to him than he did to you because you are re-raising a raise by the only other stack that can hurt you. Again, if he calls then you still have 1800 and much more if you hit A or a K. If he folds you pick up another 675 chips and take a clear lead from which you can dominate the tournament.