Hitman/Gang Contracts

I was thinking that a hitman contract system might be an interesting revenue idea for criminal based players. The contracts would solely be on NPC's and not players and they should only be accessed similarly to how boosting works where you select the tier of target to assassinate. I know people would argue this isn't RP to an extent however people are paid for these type of services and with it being GTA I'd say its not out the realm of possibility