Koyama, i agree that rewarding someone that stay alive is a good idea and it's logical somehow.
But, you know the players, i guess we will see more leechers that will try to hide somewhere to not be killed... May be if you make 2-3 kills in the round and you don't die you don't pay upkeep. I don't know, i really like the actual system and i'm not for a e-peen rewarding system, but may be something can be found.