Eliminating a player is pretty hard. Actively killing them is way harder then breaking their spirit.
1. The first thing that comes to mind is just 20 NP. An early kill like that would allow a player to then fund others. (Though it should probably be a % of the games goal since 20 could mean a lot more in some games then others, so 10% in this case).
2. Alternatively it can be the same reward in spirit but proportional. Maybe a formula like 10% of the total in game NP goal minus the progression toward that goal. That way a player with 180 NP who eliminates a player doesn't automatically win. in this case they would only be awarded 2 NP [(200-180)*.1]. Not much, but still useful.
3. Another alternative is to treat it like a bounty. So instead of the rather arbitrary 10% figure, it could be modified by the number of initial players in the game. In a 10 player game with a total goal of 200, each player is worth 20 NP (200 divided by 10). in a 6 player game with a goal of 150 each player is worth 25. etc etc.
4. Then you could still add the modifier I mentioned in point 2 to balance out leaders.
5. it would have to be tested, but you could maybe do the same thing for resigned or auto eliminated players as well, but divide the total bounty up and give it to each surviving player thereby artificially speeding up the game. This may have bad side effects, but I'd like to try it.
6. I could keep going but i'll stop now.