Sparky,

I think mixing it up once in a while is good tournament strategy. Maybe you were making that play too often though, so the other player read into that and called your bet pre-flop.

And then once he bet the 300, he's basically invested over half his chips into this hand, the blinds are pretty high for his stack, I don't think you were gonna shake him with your over the top bet.

IMHO, if you were willing to risk your chips to buy this pot, I would have made the all-in bet right after the flop and hope he gets out.

Or, then, folded to his 300 bet, since he probably wasn't going to go anywhere.