Rewards for killing players with more play time

[Tylerr]

I want players to get money for killing other players in my hardcore server, and the players with more playtime to be worth more.

on death of player:
attacker is a player
add 10 to attacker's balance

That simple script would give $10 for each kill, but I wouldn't know how to reward varying levels of money for killing the people with the most play time.

Thanks.

 

[EliPlayz32]

This might work

Every 1 second:
    add 1 to {_playtime.%player%::*}

On kill player:
        if {_playtime.%player%::*} of the targeted player is greater than 9:
            make console execute the command "<economy command>"