Well, here's how I'd work the format with a $50K jackpot:
Each Mob member knocked out is worth $250. There are three helps, but each one costs a set amount of money (Ask the Mob and Poll the Mob each cost $2500, while a "Switch the Question" costs $5K), which then goes into the Mob's "bank" to split at the end of the game.
If a contestant wants to walk, they give up half of their bank to the Mob. If they answer incorrectly, the Mob gets the 80/20 split of the contestant's bank.
If the contestant knocks out all 100 members of the Mob, their bank is doubled.