How about a DM zone where you fight each other, and last surviver wins, the Surviver gets a certain amount of money, example, if the surviver won without killing anyone gets 10k, if he killed someone, gets 2k, (If he won by killing only 1 person gets 12k, 10 gets 30k etc, etc), if he killed everyone he gets 10k + 2k x *Random Amount of players*,
He gets 5k as bonus, if he won flawlessly, his reward gets doubled, if you get what I mean.
Or if he killed all players won flawlessly bonus amount if money would get... Lets say 50k.
B-T-W
The Amount of money you get rewarded should not be exact like I said, just an Example.
And its not necessary to get Bonus if you win flawlessly or killed all players...
I am just giving an idea...
P.S.
You should disable Player to Armour and Health...
Then it would be kinda boring...