$35+15 live bounty tourney hand

[vikefan24]

10 handed, I'm two to the right of the button, third hand of the tourney, blinds 25/50, starting stacks 2000. I have KJo, two limpers and I call as do both blinds. Flop AQ9 rainbow, checked around. Turn 10, two checks, one guy bets 100, I make it 300, everyone else folds, he calls. River 9, he bets 300, I make it 1000, he goes all in. Do I have to call here, should I have just called the 300 bet?

results in white
<font color="white">He had A9..</font>