I've always thought that the skill involved in killing someone with the knife should be rewarded with a higher score.
This is an extremely simple plugin that awards 2 frags instead of 1 when you humiliate someone with the knife.
It also gives a random amount of the victims money to the killer (0%, 25%, 50%, 75% or 100%).
kdf_enabled: enable or disable de plugin (default = 1)
kdf_sounds: if it should play the "humiliation" sound (default = 1)
kdf_frags: how many additional frags are awarded for the killing (default = 1)
kdf_stealmoney: if the killer gets a random part of the victim's money (default = 1)